diff --git a/blocks/DotNetUtils.cs b/blocks/DotNetUtils.cs
index f447f029..14b9e054 100644
--- a/blocks/DotNetUtils.cs
+++ b/blocks/DotNetUtils.cs
@@ -552,8 +552,9 @@ namespace de4dot.blocks {
 					newGp.GenericParamConstraints.Add(new GenericParamConstraintUser(gpc.Constraint));
 				newMethod.GenericParams.Add(newGp);
 			}
+			newMethod.Body = new CilBody();
 			copyBodyFromTo(method, newMethod);
-			return method;
+			return newMethod;
 		}
 
 #if PORT
@@ -1303,7 +1304,6 @@ namespace de4dot.blocks {
 			return false;
 		}
 
-#if PORT
 		public static IList<Instruction> getArgPushes(IList<Instruction> instrs, int index) {
 			return getArgPushes(instrs, ref index);
 		}
@@ -1313,7 +1313,7 @@ namespace de4dot.blocks {
 				return null;
 			var startInstr = instrs[index];
 			int pushes, pops;
-			calculateStackUsage(startInstr, false, out pushes, out pops);
+			startInstr.CalculateStackUsage(false, out pushes, out pops);
 
 			index--;
 			int numArgs = pops;
@@ -1321,7 +1321,7 @@ namespace de4dot.blocks {
 			int stackSize = numArgs;
 			while (index >= 0 && args.Count != numArgs) {
 				var instr = instrs[index--];
-				calculateStackUsage(instr, false, out pushes, out pops);
+				instr.CalculateStackUsage(false, out pushes, out pops);
 				if (instr.OpCode.Code == Code.Dup) {
 					args.Add(instr);
 					stackSize--;
@@ -1349,6 +1349,7 @@ namespace de4dot.blocks {
 			return args;
 		}
 
+#if PORT
 		public static AssemblyNameReference addAssemblyReference(ModuleDefinition module, AssemblyNameReference asmRef) {
 			foreach (var modAsmRef in module.AssemblyReferences) {
 				if (modAsmRef.FullName == asmRef.FullName)
diff --git a/de4dot.code/de4dot.code.csproj b/de4dot.code/de4dot.code.csproj
index c93591eb..4859bd23 100644
--- a/de4dot.code/de4dot.code.csproj
+++ b/de4dot.code/de4dot.code.csproj
@@ -135,19 +135,19 @@
     <Compile Include="deobfuscators\CryptoObfuscator\ResourceResolver.cs" />
     <Compile Include="deobfuscators\CryptoObfuscator\StringDecrypter.cs" />
     <Compile Include="deobfuscators\CryptoObfuscator\TamperDetection.cs" />
-    <None Include="deobfuscators\DeepSea\ArrayBlockDeobfuscator.cs" />
-    <None Include="deobfuscators\DeepSea\ArrayBlockState.cs" />
-    <None Include="deobfuscators\DeepSea\AssemblyResolver.cs" />
-    <None Include="deobfuscators\DeepSea\CastDeobfuscator.cs" />
-    <None Include="deobfuscators\DeepSea\Deobfuscator.cs" />
-    <None Include="deobfuscators\DeepSea\DsConstantsReader.cs" />
-    <None Include="deobfuscators\DeepSea\DsInlinedMethodsFinder.cs" />
-    <None Include="deobfuscators\DeepSea\DsMethodCallInliner.cs" />
-    <None Include="deobfuscators\DeepSea\DsUtils.cs" />
-    <None Include="deobfuscators\DeepSea\FieldsRestorer.cs" />
-    <None Include="deobfuscators\DeepSea\ResolverBase.cs" />
-    <None Include="deobfuscators\DeepSea\ResourceResolver.cs" />
-    <None Include="deobfuscators\DeepSea\StringDecrypter.cs" />
+    <Compile Include="deobfuscators\DeepSea\ArrayBlockDeobfuscator.cs" />
+    <Compile Include="deobfuscators\DeepSea\ArrayBlockState.cs" />
+    <Compile Include="deobfuscators\DeepSea\AssemblyResolver.cs" />
+    <Compile Include="deobfuscators\DeepSea\CastDeobfuscator.cs" />
+    <Compile Include="deobfuscators\DeepSea\Deobfuscator.cs" />
+    <Compile Include="deobfuscators\DeepSea\DsConstantsReader.cs" />
+    <Compile Include="deobfuscators\DeepSea\DsInlinedMethodsFinder.cs" />
+    <Compile Include="deobfuscators\DeepSea\DsMethodCallInliner.cs" />
+    <Compile Include="deobfuscators\DeepSea\DsUtils.cs" />
+    <Compile Include="deobfuscators\DeepSea\FieldsRestorer.cs" />
+    <Compile Include="deobfuscators\DeepSea\ResolverBase.cs" />
+    <Compile Include="deobfuscators\DeepSea\ResourceResolver.cs" />
+    <Compile Include="deobfuscators\DeepSea\StringDecrypter.cs" />
     <Compile Include="deobfuscators\DeobfuscatorBase.cs" />
     <Compile Include="deobfuscators\DeobfuscatorInfoBase.cs" />
     <Compile Include="deobfuscators\DeobUtils.cs" />
diff --git a/de4dot.code/deobfuscators/DeepSea/ArrayBlockDeobfuscator.cs b/de4dot.code/deobfuscators/DeepSea/ArrayBlockDeobfuscator.cs
index a51ea0a8..c757bd9e 100644
--- a/de4dot.code/deobfuscators/DeepSea/ArrayBlockDeobfuscator.cs
+++ b/de4dot.code/deobfuscators/DeepSea/ArrayBlockDeobfuscator.cs
@@ -26,7 +26,7 @@ using de4dot.blocks.cflow;
 namespace de4dot.code.deobfuscators.DeepSea {
 	class ArrayBlockDeobfuscator : BlockDeobfuscator {
 		ArrayBlockState arrayBlockState;
-		Dictionary<VariableDefinition, ArrayBlockState.FieldInfo> localToInfo = new Dictionary<VariableDefinition, ArrayBlockState.FieldInfo>();
+		Dictionary<Local, ArrayBlockState.FieldInfo> localToInfo = new Dictionary<Local, ArrayBlockState.FieldInfo>();
 		DsConstantsReader constantsReader;
 
 		public ArrayBlockDeobfuscator(ArrayBlockState arrayBlockState) {
@@ -51,10 +51,10 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					if (!stloc.isStloc())
 						continue;
 
-					var info = arrayBlockState.getFieldInfo((FieldReference)ldsfld.Operand);
+					var info = arrayBlockState.getFieldInfo((IField)ldsfld.Operand);
 					if (info == null)
 						continue;
-					var local = DotNetUtils.getLocalVar(blocks.Locals, stloc.Instruction);
+					var local = stloc.Instruction.GetLocal(blocks.Locals);
 					if (local == null)
 						continue;
 
@@ -99,7 +99,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var ldloc = instrs[i];
 			if (!ldloc.isLdloc())
 				return false;
-			var local = DotNetUtils.getLocalVar(blocks.Locals, ldloc.Instruction);
+			var local = ldloc.Instruction.GetLocal(blocks.Locals);
 			if (local == null)
 				return false;
 			ArrayBlockState.FieldInfo info;
@@ -127,7 +127,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var ldsfld = instrs[i];
 			if (ldsfld.OpCode.Code != Code.Ldsfld)
 				return false;
-			var info = arrayBlockState.getFieldInfo(ldsfld.Operand as FieldReference);
+			var info = arrayBlockState.getFieldInfo(ldsfld.Operand as IField);
 			if (info == null)
 				return false;
 
@@ -153,7 +153,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var ldsfld = instrs[i];
 			if (ldsfld.OpCode.Code != Code.Ldsfld)
 				return false;
-			var info = arrayBlockState.getFieldInfo(ldsfld.Operand as FieldReference);
+			var info = arrayBlockState.getFieldInfo(ldsfld.Operand as IField);
 			if (info == null)
 				return false;
 
diff --git a/de4dot.code/deobfuscators/DeepSea/ArrayBlockState.cs b/de4dot.code/deobfuscators/DeepSea/ArrayBlockState.cs
index 666e25b3..a0a9e3b1 100644
--- a/de4dot.code/deobfuscators/DeepSea/ArrayBlockState.cs
+++ b/de4dot.code/deobfuscators/DeepSea/ArrayBlockState.cs
@@ -20,12 +20,11 @@
 using System.Collections.Generic;
 using dot10.DotNet;
 using dot10.DotNet.Emit;
-using Mono.Cecil.Metadata;
 using de4dot.blocks;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	class ArrayBlockState {
-		ModuleDefinition module;
+		ModuleDefMD module;
 		FieldDefinitionAndDeclaringTypeDict<FieldInfo> fieldToInfo = new FieldDefinitionAndDeclaringTypeDict<FieldInfo>();
 
 		public class FieldInfo {
@@ -44,7 +43,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			get { return fieldToInfo.Count != 0; }
 		}
 
-		public ArrayBlockState(ModuleDefinition module) {
+		public ArrayBlockState(ModuleDefMD module) {
 			this.module = module;
 		}
 
@@ -65,22 +64,22 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var instructions = method.Body.Instructions;
 			for (int i = 0; i < instructions.Count; i++) {
 				var ldci4 = instructions[i];
-				if (!DotNetUtils.isLdcI4(ldci4))
+				if (!ldci4.IsLdcI4())
 					continue;
 				i++;
 				var instrs = DotNetUtils.getInstructions(instructions, i, OpCodes.Newarr, OpCodes.Dup, OpCodes.Ldtoken, OpCodes.Call, OpCodes.Stsfld);
 				if (instrs == null)
 					continue;
 
-				var arrayType = instrs[0].Operand as TypeReference;
-				if (arrayType == null || arrayType.EType != ElementType.U1)
+				var arrayType = instrs[0].Operand as ITypeDefOrRef;
+				if (arrayType == null || (arrayType.FullName != "System.Byte" && !arrayType.DefinitionAssembly.IsCorLib()))
 					continue;
 
 				var arrayInitField = instrs[2].Operand as FieldDef;
 				if (arrayInitField == null || arrayInitField.InitialValue == null || arrayInitField.InitialValue.Length == 0)
 					continue;
 
-				var calledMethod = instrs[3].Operand as MethodReference;
+				var calledMethod = instrs[3].Operand as IMethod;
 				if (calledMethod == null || calledMethod.FullName != "System.Void System.Runtime.CompilerServices.RuntimeHelpers::InitializeArray(System.Array,System.RuntimeFieldHandle)")
 					continue;
 
@@ -96,7 +95,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return foundField;
 		}
 
-		public FieldInfo getFieldInfo(FieldReference fieldRef) {
+		public FieldInfo getFieldInfo(IField fieldRef) {
 			if (fieldRef == null)
 				return null;
 			return fieldToInfo.find(fieldRef);
@@ -118,7 +117,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					removedFields.Add(fieldInfo.arrayInitField);
 				}
 				fieldInfo.arrayInitField.InitialValue = new byte[1];
-				fieldInfo.arrayInitField.FieldType = module.TypeSystem.Byte;
+				fieldInfo.arrayInitField.FieldSig.Type = module.CorLibTypes.Byte;
 			}
 
 			IList<Instruction> allInstructions;
@@ -148,7 +147,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var call = instrs[i + 4];
 					if (call.OpCode.Code != Code.Call)
 						continue;
-					var calledMethod = call.Operand as MethodReference;
+					var calledMethod = call.Operand as IMethod;
 					if (calledMethod == null || calledMethod.FullName != "System.Void System.Runtime.CompilerServices.RuntimeHelpers::InitializeArray(System.Array,System.RuntimeFieldHandle)")
 						continue;
 					var stsfld = instrs[i + 5];
@@ -174,7 +173,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 						continue;
 
 					foreach (var instr in method.Body.Instructions) {
-						var field = instr.Operand as FieldReference;
+						var field = instr.Operand as IField;
 						if (field == null)
 							continue;
 						var fieldInfo = fieldToInfo.find(field);
diff --git a/de4dot.code/deobfuscators/DeepSea/AssemblyResolver.cs b/de4dot.code/deobfuscators/DeepSea/AssemblyResolver.cs
index 6a777f93..8805c058 100644
--- a/de4dot.code/deobfuscators/DeepSea/AssemblyResolver.cs
+++ b/de4dot.code/deobfuscators/DeepSea/AssemblyResolver.cs
@@ -75,7 +75,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			get { return decryptMethod; }
 		}
 
-		public AssemblyResolver(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob)
+		public AssemblyResolver(ModuleDefMD module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob)
 			: base(module, simpleDeobfuscator, deob) {
 		}
 
@@ -128,11 +128,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		static bool isV3SL(MethodDef handler) {
 			var instrs = handler.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 3; i++) {
-				if (!DotNetUtils.isLdloc(instrs[i]))
+				if (!instrs[i].IsLdloc())
 					continue;
 				if (instrs[i + 1].OpCode.Code != Code.Add)
 					continue;
-				if (!DotNetUtils.isLdcI4(instrs[i + 2]))
+				if (!instrs[i + 2].IsLdcI4())
 					continue;
 				if (instrs[i + 3].OpCode.Code != Code.And)
 					continue;
@@ -144,11 +144,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		static bool isV41SL(MethodDef handler) {
 			var instrs = handler.Body.Instructions;
 			for (int i = 0; i < instrs.Count; i++) {
-				if (!DotNetUtils.isLdcI4(instrs[i]) || DotNetUtils.getLdcI4Value(instrs[i]) != 5)
+				if (!instrs[i].IsLdcI4() || instrs[i].GetLdcI4Value() != 5)
 					continue;
 				if (instrs[i + 1].OpCode.Code != Code.And)
 					continue;
-				if (!DotNetUtils.isLdcI4(instrs[i + 2]) || DotNetUtils.getLdcI4Value(instrs[i + 2]) != 0x1F)
+				if (!instrs[i + 2].IsLdcI4() || instrs[i + 2].GetLdcI4Value() != 0x1F)
 					continue;
 				if (instrs[i + 3].OpCode.Code != Code.And)
 					continue;
@@ -237,18 +237,18 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					return false;
 
 				var ldci4_len = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4_len))
+				if (!ldci4_len.IsLdcI4())
 					return false;
-				if (DotNetUtils.getLdcI4Value(ldci4_len) != field.InitialValue.Length)
+				if (ldci4_len.GetLdcI4Value() != field.InitialValue.Length)
 					return false;
 
 				var ldci4_magic = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4_magic))
+				if (!ldci4_magic.IsLdcI4())
 					return false;
-				int magic = DotNetUtils.getLdcI4Value(ldci4_magic);
+				int magic = ldci4_magic.GetLdcI4Value();
 
 				var call = instrs[index++];
-				if (call.OpCode.Code == Code.Tail)
+				if (call.OpCode.Code == Code.Tailcall)
 					call = instrs[index++];
 				if (call.OpCode.Code != Code.Call)
 					return false;
@@ -274,13 +274,13 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				int index = i;
 
 				var ldci4_len = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4_len))
+				if (!ldci4_len.IsLdcI4())
 					continue;
 				if (instrs[index++].OpCode.Code != Code.Newarr)
 					continue;
-				if (!DotNetUtils.isStloc(instrs[index++]))
+				if (!instrs[index++].IsStloc())
 					continue;
-				if (!DotNetUtils.isLdloc(instrs[index++]))
+				if (!instrs[index++].IsLdloc())
 					continue;
 
 				var ldtoken = instrs[index++];
@@ -293,7 +293,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var call1 = instrs[index++];
 				if (call1.OpCode.Code != Code.Call)
 					continue;
-				if (!DotNetUtils.isMethod(call1.Operand as MethodReference, "System.Void", "(System.Array,System.RuntimeFieldHandle)"))
+				if (!DotNetUtils.isMethod(call1.Operand as IMethod, "System.Void", "(System.Array,System.RuntimeFieldHandle)"))
 					continue;
 
 				int callIndex = getCallDecryptMethodIndex(instrs, index);
@@ -351,19 +351,19 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var instrs = method.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 4; i++) {
 				int index = i;
-				if (!DotNetUtils.isLdloc(instrs[index++]))
+				if (!instrs[index++].IsLdloc())
 					continue;
 				var ldarg = instrs[index++];
-				if (!DotNetUtils.isLdarg(ldarg))
+				if (!ldarg.IsLdarg())
 					continue;
 				if (instrs[index++].OpCode.Code != Code.Add)
 					continue;
 				var ldci4 = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4))
+				if (!ldci4.IsLdcI4())
 					continue;
-				if (DotNetUtils.getLdcI4Value(ldci4) != 0xFF)
+				if (ldci4.GetLdcI4Value() != 0xFF)
 					continue;
-				return DotNetUtils.getArgIndex(ldarg);
+				return ldarg.GetParameterIndex();
 			}
 			return -1;
 		}
@@ -375,16 +375,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				if (instrs[index++].OpCode.Code != Code.Div)
 					continue;
 				var ldarg = instrs[index++];
-				if (!DotNetUtils.isLdarg(ldarg))
+				if (!ldarg.IsLdarg())
 					continue;
 				if (instrs[index++].OpCode.Code != Code.Add)
 					continue;
 				var ldci4 = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4))
+				if (!ldci4.IsLdcI4())
 					continue;
-				if (DotNetUtils.getLdcI4Value(ldci4) != 0xFF)
+				if (ldci4.GetLdcI4Value() != 0xFF)
 					continue;
-				return DotNetUtils.getArgIndex(ldarg);
+				return ldarg.GetParameterIndex();
 			}
 			return -1;
 		}
@@ -399,8 +399,8 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					break;
 				if (instr.OpCode.Code != Code.Call)
 					continue;
-				var calledMethod = instr.Operand as MethodReference;
-				if (calledMethod == null || calledMethod.Parameters.Count < 2)
+				var calledMethod = instr.Operand as IMethod;
+				if (calledMethod == null || calledMethod.MethodSig.GetParamCount() < 2)
 					continue;
 
 				return i;
@@ -457,7 +457,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var resource = tmp as EmbeddedResource;
 				if (resource == null)
 					continue;
-				if (!Regex.IsMatch(resource.Name, @"^[0-9A-F]{40}$"))
+				if (!Regex.IsMatch(resource.Name.String, @"^[0-9A-F]{40}$"))
 					continue;
 				var info = getAssemblyInfo(resource, decrypter);
 				if (info == null)
@@ -479,9 +479,9 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		}
 
 		AssemblyInfo getAssemblyInfo(byte[] decryptedData, EmbeddedResource resource) {
-			var asm = AssemblyDefinition.ReadAssembly(new MemoryStream(decryptedData));
-			var fullName = asm.Name.FullName;
-			var simpleName = asm.Name.Name;
+			var asm = AssemblyDef.Load(decryptedData);
+			var fullName = asm.FullName;
+			var simpleName = asm.Name.String;
 			var extension = DeobUtils.getExtension(asm.Modules[0].Kind);
 			return new AssemblyInfo(decryptedData, fullName, simpleName, extension, resource);
 		}
@@ -496,7 +496,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var decrypted = decrypter(fieldInfo.field.InitialValue, fieldInfo.magic);
 				infos.Add(getAssemblyInfo(decrypted, null));
 				fieldInfo.field.InitialValue = new byte[1];
-				fieldInfo.field.FieldType = module.TypeSystem.Byte;
+				fieldInfo.field.FieldSig.Type = module.CorLibTypes.Byte;
 			}
 
 			return infos;
diff --git a/de4dot.code/deobfuscators/DeepSea/CastDeobfuscator.cs b/de4dot.code/deobfuscators/DeepSea/CastDeobfuscator.cs
index 2458b358..798debcc 100644
--- a/de4dot.code/deobfuscators/DeepSea/CastDeobfuscator.cs
+++ b/de4dot.code/deobfuscators/DeepSea/CastDeobfuscator.cs
@@ -27,14 +27,14 @@ using dot10.DotNet.Emit;
 namespace de4dot.code.deobfuscators.DeepSea {
 	class CastDeobfuscator : IBlocksDeobfuscator {
 		Blocks blocks;
-		Dictionary<VariableDefinition, LocalInfo> localInfos = new Dictionary<VariableDefinition, LocalInfo>();
+		Dictionary<Local, LocalInfo> localInfos = new Dictionary<Local, LocalInfo>();
 
 		class LocalInfo {
-			public readonly VariableDefinition local;
-			TypeReference type;
+			public readonly Local local;
+			ITypeDefOrRef type;
 			bool isValid;
 
-			public TypeReference CastType {
+			public ITypeDefOrRef CastType {
 				get { return type; }
 				set {
 					if (!isValid)
@@ -45,7 +45,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 						return;
 					}
 
-					if (type != null && !MemberReferenceHelper.compareTypes(type, value)) {
+					if (type != null && !new SigComparer().Equals(type, value)) {
 						invalid();
 						return;
 					}
@@ -54,7 +54,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				}
 			}
 
-			public LocalInfo(VariableDefinition local) {
+			public LocalInfo(Local local) {
 				this.local = local;
 				this.isValid = true;
 			}
@@ -92,13 +92,13 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				for (int i = 0; i < instrs.Count - 1; i++) {
 					var instr = instrs[i];
 					if (instr.OpCode.Code == Code.Ldloca || instr.OpCode.Code == Code.Ldloca_S) {
-						var local = instr.Operand as VariableDefinition;
+						var local = instr.Operand as Local;
 						if (local == null)
 							continue;
 						localInfos[local].invalid();
 					}
 					else if (instr.isLdloc()) {
-						var local = DotNetUtils.getLocalVar(blocks.Locals, instr.Instruction);
+						var local = instr.Instruction.GetLocal(blocks.Locals);
 						if (local == null)
 							continue;
 						var localInfo = localInfos[local];
@@ -120,7 +120,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			foreach (var info in localInfos.Values) {
 				if (info.CastType == null)
 					continue;
-				info.local.VariableType = info.CastType;
+				info.local.Type = info.CastType.ToTypeSig();
 			}
 
 			if (changed) {
@@ -137,18 +137,18 @@ namespace de4dot.code.deobfuscators.DeepSea {
 						}
 
 						if (instr.isLdarg())
-							addCast(block, castIndex, i + 1, DotNetUtils.getArgType(blocks.Method, instr.Instruction));
+							addCast(block, castIndex, i + 1, instr.Instruction.GetArgumentType(blocks.Method.MethodSig, blocks.Method.DeclaringType));
 						else if (instr.OpCode.Code == Code.Ldfld || instr.OpCode.Code == Code.Ldsfld) {
-							var field = instr.Operand as FieldReference;
+							var field = instr.Operand as IField;
 							if (field == null)
 								continue;
-							addCast(block, castIndex, i + 1, field.FieldType);
+							addCast(block, castIndex, i + 1, field.FieldSig.GetFieldType());
 						}
 						else if (instr.OpCode.Code == Code.Call || instr.OpCode.Code == Code.Callvirt) {
-							var calledMethod = instr.Operand as MethodReference;
+							var calledMethod = instr.Operand as IMethod;
 							if (calledMethod == null || !DotNetUtils.hasReturnValue(calledMethod))
 								continue;
-							addCast(block, castIndex, i + 1, calledMethod.MethodReturnType.ReturnType);
+							addCast(block, castIndex, i + 1, calledMethod.MethodSig.GetRetType());
 						}
 					}
 				}
@@ -157,7 +157,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return changed;
 		}
 
-		bool addCast(Block block, int castIndex, int index, TypeReference type) {
+		bool addCast(Block block, int castIndex, int index, TypeSig type) {
 			if (type == null)
 				return false;
 			if (castIndex >= block.Instructions.Count || index >= block.Instructions.Count)
@@ -165,14 +165,14 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var stloc = block.Instructions[index];
 			if (!stloc.isStloc())
 				return false;
-			var local = DotNetUtils.getLocalVar(blocks.Locals, stloc.Instruction);
+			var local = stloc.Instruction.GetLocal(blocks.Locals);
 			if (local == null)
 				return false;
 			var localInfo = localInfos[local];
 			if (localInfo.CastType == null)
 				return false;
 
-			if (!MemberReferenceHelper.compareTypes(localInfo.CastType, type))
+			if (!new SigComparer().Equals(localInfo.CastType, type))
 				block.insert(castIndex, new Instruction(OpCodes.Castclass, localInfo.CastType));
 			return true;
 		}
@@ -190,7 +190,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var ldloc = instrs[i];
 					if (!ldloc.isLdloc())
 						continue;
-					var local = DotNetUtils.getLocalVar(blocks.Locals, ldloc.Instruction);
+					var local = ldloc.Instruction.GetLocal(blocks.Locals);
 					if (local == null)
 						continue;
 					var localInfo = localInfos[local];
@@ -204,10 +204,10 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return instr.OpCode.Code == Code.Castclass || instr.OpCode.Code == Code.Isinst;
 		}
 
-		static TypeReference getCastType(Instr instr) {
+		static ITypeDefOrRef getCastType(Instr instr) {
 			if (!isCast(instr))
 				return null;
-			return instr.Operand as TypeReference;
+			return instr.Operand as ITypeDefOrRef;
 		}
 	}
 }
diff --git a/de4dot.code/deobfuscators/DeepSea/DsInlinedMethodsFinder.cs b/de4dot.code/deobfuscators/DeepSea/DsInlinedMethodsFinder.cs
index 8809bba4..c4c5f5b5 100644
--- a/de4dot.code/deobfuscators/DeepSea/DsInlinedMethodsFinder.cs
+++ b/de4dot.code/deobfuscators/DeepSea/DsInlinedMethodsFinder.cs
@@ -22,7 +22,7 @@ using dot10.DotNet;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	static class DsInlinedMethodsFinder {
-		public static List<MethodDef> find(ModuleDefinition module, IEnumerable<MethodDef> notInlinedMethods) {
+		public static List<MethodDef> find(ModuleDefMD module, IEnumerable<MethodDef> notInlinedMethods) {
 			var notInlinedMethodsDict = new Dictionary<MethodDef, bool>();
 			foreach (var method in notInlinedMethods)
 				notInlinedMethodsDict[method] = true;
diff --git a/de4dot.code/deobfuscators/DeepSea/DsMethodCallInliner.cs b/de4dot.code/deobfuscators/DeepSea/DsMethodCallInliner.cs
index 66bc416c..b5082297 100644
--- a/de4dot.code/deobfuscators/DeepSea/DsMethodCallInliner.cs
+++ b/de4dot.code/deobfuscators/DeepSea/DsMethodCallInliner.cs
@@ -20,15 +20,14 @@
 using System.Collections.Generic;
 using dot10.DotNet;
 using dot10.DotNet.Emit;
-using Mono.Cecil.Metadata;
 using de4dot.blocks;
 using de4dot.blocks.cflow;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	class DsMethodCallInliner : MethodCallInlinerBase {
 		InstructionEmulator instructionEmulator = new InstructionEmulator();
-		List<ParameterDefinition> parameters;
-		ParameterDefinition arg1, arg2;
+		IList<Parameter> parameters;
+		Parameter arg1, arg2;
 		Value returnValue;
 		MethodDef methodToInline;
 		CachedCflowDeobfuscator cflowDeobfuscator;
@@ -73,14 +72,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		bool inlineMethod(MethodDef methodToInline, int instrIndex, int const1, int const2) {
 			this.methodToInline = methodToInline = cflowDeobfuscator.deobfuscate(methodToInline);
 
-			parameters = DotNetUtils.getParameters(methodToInline);
+			parameters = methodToInline.Parameters;
 			arg1 = parameters[parameters.Count - 2];
 			arg2 = parameters[parameters.Count - 1];
 			returnValue = null;
 
 			instructionEmulator.init(methodToInline);
 			foreach (var arg in parameters) {
-				if (arg.ParameterType.EType >= ElementType.Boolean && arg.ParameterType.EType <= ElementType.U4)
+				if (!arg.IsNormalMethodParameter)
+					continue;
+				if (arg.Type.ElementType >= ElementType.Boolean && arg.Type.ElementType <= ElementType.U4)
 					instructionEmulator.setArg(arg, new Int32Value(0));
 			}
 			instructionEmulator.setArg(arg1, new Int32Value(const1));
@@ -157,7 +158,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				case Code.Ldarg_1:
 				case Code.Ldarg_2:
 				case Code.Ldarg_3:
-					var arg = DotNetUtils.getParameter(parameters, instr);
+					var arg = instr.GetParameter(parameters);
 					if (arg != arg1 && arg != arg2) {
 						if (!allowUnknownArgs)
 							goto done;
@@ -269,7 +270,7 @@ done:
 
 		bool emulateToReturn(int index, Instruction lastInstr) {
 			int pushes, pops;
-			DotNetUtils.calculateStackUsage(lastInstr, false, out pushes, out pops);
+			lastInstr.CalculateStackUsage(false, out pushes, out pops);
 			for (int i = 0; i < pops; i++)
 				instructionEmulator.pop();
 
@@ -297,22 +298,22 @@ done:
 		public static bool canInline(MethodDef method) {
 			if (method == null || method.Body == null)
 				return false;
-			if (method.Attributes != (MethodAttributes.Assembly | MethodAttributes.Static))
+			if (method.Flags != (MethodAttributes.Assembly | MethodAttributes.Static))
 				return false;
-			if (method.GenericParameters.Count > 0)
+			if (method.GenericParams.Count > 0)
 				return false;
 			if (method.Body.ExceptionHandlers.Count > 0)
 				return false;
 
-			var parameters = method.Parameters;
+			var parameters = method.MethodSig.GetParams();
 			int paramCount = parameters.Count;
 			if (paramCount < 2)
 				return false;
 			var param1 = parameters[paramCount - 1];
 			var param2 = parameters[paramCount - 2];
-			if (!isIntType(param1.ParameterType.EType))
+			if (!isIntType(param1.ElementType))
 				return false;
-			if (!isIntType(param2.ParameterType.EType))
+			if (!isIntType(param2.ElementType))
 				return false;
 
 			return true;
diff --git a/de4dot.code/deobfuscators/DeepSea/FieldsRestorer.cs b/de4dot.code/deobfuscators/DeepSea/FieldsRestorer.cs
index a15346a7..cef51edf 100644
--- a/de4dot.code/deobfuscators/DeepSea/FieldsRestorer.cs
+++ b/de4dot.code/deobfuscators/DeepSea/FieldsRestorer.cs
@@ -21,13 +21,12 @@ using System;
 using System.Collections.Generic;
 using dot10.DotNet;
 using dot10.DotNet.Emit;
-using Mono.Cecil.Metadata;
 using de4dot.blocks;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	// DS 4.x can move fields from a class to a struct. This class restores the fields.
 	class FieldsRestorer {
-		ModuleDefinition module;
+		ModuleDefMD module;
 		TypeDefinitionDict<List<TypeDef>> structToOwners = new TypeDefinitionDict<List<TypeDef>>();
 		FieldDefinitionAndDeclaringTypeDict<bool> structFieldsToFix = new FieldDefinitionAndDeclaringTypeDict<bool>();
 		TypeDefinitionDict<FieldDefinitionAndDeclaringTypeDict<FieldDef>> typeToFieldsDict = new TypeDefinitionDict<FieldDefinitionAndDeclaringTypeDict<FieldDef>>();
@@ -50,17 +49,17 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				return true;
 			if (type.BaseType == null)
 				return false;
-			if (type.BaseType.EType != ElementType.Object)
+			if (type.BaseType.FullName != "System.Object")
 				return false;
 			if (type.Methods.Count != 1)
 				return false;
 			var ctor = type.Methods[0];
-			if (ctor.Name != ".ctor" || ctor.Parameters.Count != 0)
+			if (ctor.Name != ".ctor" || ctor.MethodSig.GetParamCount() != 0)
 				return false;
 			return true;
 		}
 
-		public FieldsRestorer(ModuleDefinition module) {
+		public FieldsRestorer(ModuleDefMD module) {
 			this.module = module;
 		}
 
@@ -71,7 +70,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 
 				foreach (var ownerType in kv.Value) {
 					foreach (var ownerField in ownerType.Fields) {
-						if (DotNetUtils.getType(module, ownerField.FieldType) != structType)
+						if (DotNetUtils.getType(module, ownerField.FieldSig.GetFieldType()) != structType)
 							continue;
 						structFieldsToFix.add(ownerField, true);
 						break;
@@ -80,7 +79,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var fieldsDict = new FieldDefinitionAndDeclaringTypeDict<FieldDef>();
 					typeToFieldsDict.add(ownerType, fieldsDict);
 					foreach (var structField in structType.Fields) {
-						var newField = DotNetUtils.createFieldDefinition(structField.Name, structField.Attributes, structField.FieldType);
+						var newField = module.UpdateRowId(new FieldDefUser(structField.Name, structField.FieldSig.Clone(), structField.Flags));
 						ownerType.Fields.Add(newField);
 						fieldsDict.add(structField, newField);
 					}
@@ -93,16 +92,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var typeToStruct = new Dictionary<TypeDef, TypeDef>();
 			foreach (var type in module.GetTypes()) {
 				foreach (var field in getPossibleFields(type)) {
-					var fieldType = DotNetUtils.getType(module, field.FieldType);
+					var fieldType = DotNetUtils.getType(module, field.FieldSig.GetFieldType());
 					if (fieldType == null)
 						continue;
 					if (!checkBaseType(fieldType))
 						continue;
-					if ((fieldType.Attributes & ~TypeAttributes.Sealed) != TypeAttributes.NestedAssembly)
+					if ((fieldType.Flags & ~TypeAttributes.Sealed) != TypeAttributes.NestedAssembly)
 						continue;
 					if (fieldType.NestedTypes.Count > 0)
 						continue;
-					if (fieldType.GenericParameters.Count > 0)
+					if (fieldType.GenericParams.Count > 0)
 						continue;
 					if (fieldType.Fields.Count == 0)
 						continue;
@@ -127,16 +126,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				typeToStruct.TryGetValue(type, out structType);
 
 				foreach (var field in type.Fields) {
-					if (field.IsStatic || field.FieldType != structType)
-						removeType(candidates, field.FieldType);
+					if (field.IsStatic || field.FieldSig.GetFieldType().TryGetTypeDef() != structType)
+						removeType(candidates, field.FieldSig.GetFieldType());
 				}
 				foreach (var method in type.Methods) {
-					removeType(candidates, method.MethodReturnType.ReturnType);
-					foreach (var parameter in method.Parameters)
-						removeType(candidates, parameter.ParameterType);
+					removeType(candidates, method.MethodSig.GetRetType());
+					foreach (var parameter in method.MethodSig.GetParams())
+						removeType(candidates, parameter);
 					if (method.Body != null) {
-						foreach (var local in method.Body.Variables)
-							removeType(candidates, local.VariableType);
+						foreach (var local in method.Body.LocalList)
+							removeType(candidates, local.Type);
 					}
 				}
 			}
@@ -147,9 +146,9 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		IEnumerable<FieldDef> getPossibleFields(TypeDef type) {
 			var typeToFields = new TypeDefinitionDict<List<FieldDef>>();
 			foreach (var field in type.Fields) {
-				if (field.Attributes != FieldAttributes.Private)
+				if (field.Flags != FieldAttributes.Private)
 					continue;
-				var fieldType = DotNetUtils.getType(module, field.FieldType);
+				var fieldType = DotNetUtils.getType(module, field.FieldSig.GetFieldType());
 				if (fieldType == null)
 					continue;
 				if (!checkBaseType(fieldType))
@@ -169,10 +168,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		static bool checkBaseType(TypeDef type) {
 			if (type == null || type.BaseType == null)
 				return false;
-			return type.BaseType.FullName == "System.ValueType" || type.BaseType.EType == ElementType.Object;
+			var fn = type.BaseType.FullName;
+			return fn == "System.ValueType" || fn == "System.Object";
 		}
 
-		void removeType(Dictionary<TypeDef, List<TypeDef>> candidates, TypeReference type) {
+		void removeType(Dictionary<TypeDef, List<TypeDef>> candidates, TypeSig type) {
 			var typeDef = DotNetUtils.getType(module, type);
 			if (typeDef == null)
 				return;
@@ -183,15 +183,15 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			foreach (var method in type.Methods) {
 				if (method.Name == ".cctor")
 					continue;
-				if (type.BaseType != null && type.BaseType.EType == ElementType.Object && method.Name == ".ctor" && method.Parameters.Count == 0)
+				if (type.BaseType != null && type.BaseType.FullName == "System.Object" && method.Name == ".ctor" && method.MethodSig.GetParamCount() == 0)
 					continue;
 				if (!method.IsStatic)
 					return true;
-				if (method.GenericParameters.Count > 0)
+				if (method.GenericParams.Count > 0)
 					return true;
 				if (method.Body == null)
 					return true;
-				if (method.HasPInvokeInfo || method.PInvokeInfo != null)
+				if (method.ImplMap != null)
 					return true;
 			}
 			return false;
@@ -223,12 +223,12 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var instr = instrs[i];
 					if (instr.OpCode.Code != Code.Ldflda && instr.OpCode.Code != Code.Ldfld)
 						continue;
-					var structField = instr.Operand as FieldReference;
+					var structField = instr.Operand as IField;
 					if (structField == null || !structFieldsToFix.find(structField))
 						continue;
 
 					var ldStFld = instrs[findLdStFieldIndex(instrs, i + 1)];
-					ldStFld.Operand = getNewField(structField, ldStFld.Operand as FieldReference);
+					ldStFld.Operand = getNewField(structField, ldStFld.Operand as IField);
 					instrsToRemove.Add(i);
 				}
 				if (instrsToRemove.Count > 0)
@@ -246,7 +246,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var stfld = instrs[i];
 					if (stfld.OpCode.Code != Code.Stfld)
 						continue;
-					var field = stfld.Operand as FieldReference;
+					var field = stfld.Operand as IField;
 					if (field == null)
 						continue;
 					if (!structFieldsToFix.find(field))
@@ -270,7 +270,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return newInstrs;
 		}
 
-		FieldDef getNewField(FieldReference structField, FieldReference oldFieldRef) {
+		FieldDef getNewField(IField structField, IField oldFieldRef) {
 			var fieldsDict = typeToFieldsDict.find(structField.DeclaringType);
 			if (fieldsDict == null)
 				throw new ApplicationException("Could not find structField declaringType");
@@ -291,7 +291,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					return i;
 
 				int pushes, pops;
-				DotNetUtils.calculateStackUsage(instr.Instruction, false, out pushes, out pops);
+				instr.Instruction.CalculateStackUsage(false, out pushes, out pops);
 				stack -= pops;
 				if (stack < 0)
 					break;
diff --git a/de4dot.code/deobfuscators/DeepSea/ResolverBase.cs b/de4dot.code/deobfuscators/DeepSea/ResolverBase.cs
index 04f6b68a..ea764de2 100644
--- a/de4dot.code/deobfuscators/DeepSea/ResolverBase.cs
+++ b/de4dot.code/deobfuscators/DeepSea/ResolverBase.cs
@@ -25,7 +25,7 @@ using de4dot.blocks;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	abstract class ResolverBase {
-		protected ModuleDefinition module;
+		protected ModuleDefMD module;
 		protected ISimpleDeobfuscator simpleDeobfuscator;
 		protected IDeobfuscator deob;
 		protected MethodDef initMethod;
@@ -44,7 +44,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			get { return initMethod != null; }
 		}
 
-		public ResolverBase(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob) {
+		public ResolverBase(ModuleDefMD module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob) {
 			this.module = module;
 			this.frameworkType = DotNetUtils.getFrameworkType(module);
 			this.simpleDeobfuscator = simpleDeobfuscator;
diff --git a/de4dot.code/deobfuscators/DeepSea/ResourceResolver.cs b/de4dot.code/deobfuscators/DeepSea/ResourceResolver.cs
index a8b99866..9850e576 100644
--- a/de4dot.code/deobfuscators/DeepSea/ResourceResolver.cs
+++ b/de4dot.code/deobfuscators/DeepSea/ResourceResolver.cs
@@ -83,7 +83,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			get { return data30 != null ? data30.resource : null; }
 		}
 
-		public ResourceResolver(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob)
+		public ResourceResolver(ModuleDefMD module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob)
 			: base(module, simpleDeobfuscator, deob) {
 		}
 
@@ -145,7 +145,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				magicArgIndex = getMagicArgIndex41Trial(info.handler);
 				data41.isTrial = true;
 			}
-			var asmVer = module.Assembly.Name.Version;
+			var asmVer = module.Assembly.Version;
 			if (magicArgIndex < 0 || magicArgIndex >= info.args.Count)
 				return false;
 			var val = info.args[magicArgIndex];
@@ -165,16 +165,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				if (add.OpCode.Code != Code.Add)
 					continue;
 				var ldarg = instrs[i + 1];
-				if (!DotNetUtils.isLdarg(ldarg))
+				if (!ldarg.IsLdarg())
 					continue;
 				var sub = instrs[i + 2];
 				if (sub.OpCode.Code != Code.Sub)
 					continue;
 				var ldci4 = instrs[i + 3];
-				if (!DotNetUtils.isLdcI4(ldci4) || DotNetUtils.getLdcI4Value(ldci4) != 0xFF)
+				if (!ldci4.IsLdcI4() || ldci4.GetLdcI4Value() != 0xFF)
 					continue;
 
-				return DotNetUtils.getArgIndex(ldarg);
+				return ldarg.GetParameterIndex();
 			}
 			return -1;
 		}
@@ -183,14 +183,14 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var instrs = method.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 2; i++) {
 				var ldarg = instrs[i];
-				if (!DotNetUtils.isLdarg(ldarg))
+				if (!ldarg.IsLdarg())
 					continue;
-				if (!DotNetUtils.isLdcI4(instrs[i + 1]))
+				if (!instrs[i + 1].IsLdcI4())
 					continue;
 				if (instrs[i + 2].OpCode.Code != Code.Shr)
 					continue;
 
-				return DotNetUtils.getArgIndex(ldarg);
+				return ldarg.GetParameterIndex();
 			}
 			return -1;
 		}
@@ -255,21 +255,21 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					continue;
 
 				var ldci4_len = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4_len))
+				if (!ldci4_len.IsLdcI4())
 					continue;
-				if (DotNetUtils.getLdcI4Value(ldci4_len) != field.InitialValue.Length)
+				if (ldci4_len.GetLdcI4Value() != field.InitialValue.Length)
 					continue;
 
 				if (instrs[index++].OpCode.Code != Code.Ldstr)
 					continue;
 
 				var ldci4_magic = instrs[index++];
-				if (!DotNetUtils.isLdcI4(ldci4_magic))
+				if (!ldci4_magic.IsLdcI4())
 					continue;
-				data40.magic = DotNetUtils.getLdcI4Value(ldci4_magic);
+				data40.magic = ldci4_magic.GetLdcI4Value();
 
 				var call = instrs[index++];
-				if (call.OpCode.Code == Code.Tail)
+				if (call.OpCode.Code == Code.Tailcall)
 					call = instrs[index++];
 				if (call.OpCode.Code != Code.Call)
 					continue;
@@ -322,7 +322,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				if (data30.resource == null)
 					return false;
 
-				DeobUtils.decryptAndAddResources(module, data30.resource.Name, () => decryptResourceV3(data30.resource));
+				DeobUtils.decryptAndAddResources(module, data30.resource.Name.String, () => decryptResourceV3(data30.resource));
 				rsrc = data30.resource;
 				return true;
 
@@ -341,10 +341,10 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			if (resourceField == null)
 				return false;
 
-			string name = string.Format("Embedded data field {0:X8} RVA {1:X8}", resourceField.MDToken.ToInt32(), resourceField.RVA);
+			string name = string.Format("Embedded data field {0:X8} RVA {1:X8}", resourceField.MDToken.ToInt32(), (uint)resourceField.RVA);
 			DeobUtils.decryptAndAddResources(module, name, () => decryptResourceV4(resourceField.InitialValue, magic));
 			resourceField.InitialValue = new byte[1];
-			resourceField.FieldType = module.TypeSystem.Byte;
+			resourceField.FieldSig.Type = module.CorLibTypes.Byte;
 			return true;
 		}
 	}
diff --git a/de4dot.code/deobfuscators/DeepSea/StringDecrypter.cs b/de4dot.code/deobfuscators/DeepSea/StringDecrypter.cs
index 8a9af0ec..c9e1ce15 100644
--- a/de4dot.code/deobfuscators/DeepSea/StringDecrypter.cs
+++ b/de4dot.code/deobfuscators/DeepSea/StringDecrypter.cs
@@ -22,12 +22,11 @@ using System.Collections.Generic;
 using System.Text;
 using dot10.DotNet;
 using dot10.DotNet.Emit;
-using Mono.Cecil.Metadata;
 using de4dot.blocks;
 
 namespace de4dot.code.deobfuscators.DeepSea {
 	class StringDecrypter {
-		ModuleDefinition module;
+		ModuleDefMD module;
 		MethodDefinitionAndDeclaringTypeDict<IDecrypterInfo> methodToInfo = new MethodDefinitionAndDeclaringTypeDict<IDecrypterInfo>();
 		DecrypterVersion version = DecrypterVersion.Unknown;
 
@@ -55,7 +54,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			var instrs = initMethod.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 2; i++) {
 				var ldci4 = instrs[i];
-				if (!DotNetUtils.isLdcI4(ldci4))
+				if (!ldci4.IsLdcI4())
 					continue;
 				var newarr = instrs[i + 1];
 				if (newarr.OpCode.Code != Code.Newarr)
@@ -64,13 +63,13 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					continue;
 
 				var stloc = instrs[i + 2];
-				if (!DotNetUtils.isStloc(stloc))
+				if (!stloc.IsStloc())
 					continue;
-				var local = DotNetUtils.getLocalVar(initMethod.Body.Variables, stloc);
+				var local = stloc.GetLocal(initMethod.Body.LocalList);
 
 				int startInitIndex = i;
 				i++;
-				var array = ArrayFinder.getInitializedInt16Array(DotNetUtils.getLdcI4Value(ldci4), initMethod, ref i);
+				var array = ArrayFinder.getInitializedInt16Array(ldci4.GetLdcI4Value(), initMethod, ref i);
 				if (array == null)
 					continue;
 
@@ -84,13 +83,13 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return null;
 		}
 
-		static FieldDef getStoreField(MethodDef method, int startIndex, VariableDefinition local) {
+		static FieldDef getStoreField(MethodDef method, int startIndex, Local local) {
 			var instrs = method.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 1; i++) {
 				var ldloc = instrs[i];
-				if (!DotNetUtils.isLdloc(ldloc))
+				if (!ldloc.IsLdloc())
 					continue;
-				if (DotNetUtils.getLocalVar(method.Body.Variables, ldloc) != local)
+				if (ldloc.GetLocal(method.Body.LocalList) != local)
 					continue;
 
 				var stsfld = instrs[i + 1];
@@ -110,16 +109,16 @@ namespace de4dot.code.deobfuscators.DeepSea {
 		static bool findMagic(MethodDef method, out int arg1, out int arg2, out int magic) {
 			var instrs = method.Body.Instructions;
 			for (int i = 0; i < instrs.Count - 3; i++) {
-				if ((arg1 = DotNetUtils.getArgIndex(instrs[i])) < 0)
+				if ((arg1 = instrs[i].GetParameterIndex()) < 0)
 					continue;
 				var ldci4 = instrs[i + 1];
-				if (!DotNetUtils.isLdcI4(ldci4))
+				if (!ldci4.IsLdcI4())
 					continue;
 				if (instrs[i + 2].OpCode.Code != Code.Xor)
 					continue;
-				if ((arg2 = DotNetUtils.getArgIndex(instrs[i + 3])) < 0)
+				if ((arg2 = instrs[i + 3].GetParameterIndex()) < 0)
 					continue;
-				magic = DotNetUtils.getLdcI4Value(ldci4);
+				magic = ldci4.GetLdcI4Value();
 				return true;
 			}
 			arg1 = arg2 = 0;
@@ -139,7 +138,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var call = instrs[i + 1];
 				if (call.OpCode.Code != Code.Call)
 					continue;
-				var calledMethod = call.Operand as MethodReference;
+				var calledMethod = call.Operand as IMethod;
 				if (calledMethod == null)
 					continue;
 				if (calledMethod.ToString() != "System.Void System.Runtime.CompilerServices.RuntimeHelpers::InitializeArray(System.Array,System.RuntimeFieldHandle)")
@@ -163,11 +162,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 
 			class ArrayInfo {
 				public int sizeInElems;
-				public TypeReference elementType;
+				public ITypeDefOrRef elementType;
 				public FieldDef initField;
 				public FieldDef field;
 
-				public ArrayInfo(int sizeInElems, TypeReference elementType, FieldDef initField, FieldDef field) {
+				public ArrayInfo(int sizeInElems, ITypeDefOrRef elementType, FieldDef initField, FieldDef field) {
 					this.sizeInElems = sizeInElems;
 					this.elementType = elementType;
 					this.initField = initField;
@@ -197,11 +196,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			}
 
 			static bool checkMethodSignature(MethodDef method) {
-				if (method.MethodReturnType.ReturnType.EType != ElementType.String)
+				if (method.MethodSig.GetRetType().GetElementType() != ElementType.String)
 					return false;
 				int count = 0;
-				foreach (var arg in method.Parameters) {
-					if (arg.ParameterType.EType == ElementType.I4)
+				foreach (var arg in method.MethodSig.GetParams()) {
+					if (arg.ElementType == ElementType.I4)
 						count++;
 				}
 				return count >= 2;
@@ -254,9 +253,9 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					int index = i;
 
 					var ldci4 = instrs[index++];
-					if (!DotNetUtils.isLdcI4(ldci4))
+					if (!ldci4.IsLdcI4())
 						continue;
-					if (DotNetUtils.getLdcI4Value(ldci4) != 0xFF)
+					if (ldci4.GetLdcI4Value() != 0xFF)
 						continue;
 
 					if (instrs[index++].OpCode.Code != Code.And)
@@ -265,13 +264,13 @@ namespace de4dot.code.deobfuscators.DeepSea {
 						continue;
 
 					var ldci4_2 = instrs[index++];
-					if (!DotNetUtils.isLdcI4(ldci4_2))
+					if (!ldci4_2.IsLdcI4())
 						continue;
 
 					if (findNextFieldUse(method, index) < 0)
 						continue;
 
-					return DotNetUtils.getLdcI4Value(ldci4_2);
+					return ldci4_2.GetLdcI4Value();
 				}
 				return -1;
 			}
@@ -282,7 +281,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var instr = instrs[i];
 					if (instr.OpCode.Code != Code.Ldsfld && instr.OpCode.Code != Code.Stsfld)
 						continue;
-					var field = instr.Operand as FieldReference;
+					var field = instr.Operand as IField;
 					if (!fields.find(field))
 						return -1;
 
@@ -295,15 +294,15 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var instructions = method.Body.Instructions;
 				for (int i = 0; i < instructions.Count; i++) {
 					var ldci4_arraySizeInBytes = instructions[i];
-					if (!DotNetUtils.isLdcI4(ldci4_arraySizeInBytes))
+					if (!ldci4_arraySizeInBytes.IsLdcI4())
 						continue;
 					i++;
 					var instrs = DotNetUtils.getInstructions(instructions, i, OpCodes.Newarr, OpCodes.Dup, OpCodes.Ldtoken, OpCodes.Call, OpCodes.Stsfld);
 					if (instrs == null)
 						continue;
 
-					int sizeInBytes = DotNetUtils.getLdcI4Value(ldci4_arraySizeInBytes);
-					var elementType = instrs[0].Operand as TypeReference;
+					int sizeInBytes = ldci4_arraySizeInBytes.GetLdcI4Value();
+					var elementType = instrs[0].Operand as ITypeDefOrRef;
 					var initField = instrs[2].Operand as FieldDef;
 					var field = instrs[4].Operand as FieldDef;
 					if (elementType == null)
@@ -319,11 +318,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			}
 
 			short[] findKey() {
-				if (cctor.Module.Assembly == null)
+				if (cctor.OwnerModule.Assembly == null)
 					return null;
-				var pkt = cctor.Module.Assembly.Name.PublicKeyToken;
-				if (pkt != null && pkt.Length > 0)
-					return getPublicKeyTokenKey(pkt);
+				var pkt = cctor.OwnerModule.Assembly.PublicKeyToken;
+				if (!PublicKeyBase.IsNullOrEmpty2(pkt))
+					return getPublicKeyTokenKey(pkt.Data);
 				return findKey(cctor);
 			}
 
@@ -380,7 +379,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 
 			public void cleanup() {
 				arrayInfo.initField.InitialValue = new byte[1];
-				arrayInfo.initField.FieldType = arrayInfo.initField.Module.TypeSystem.Byte;
+				arrayInfo.initField.FieldSig.Type = arrayInfo.initField.OwnerModule.CorLibTypes.Byte;
 				removeInitializeArrayCall(cctor, arrayInfo.initField);
 			}
 		}
@@ -447,9 +446,9 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var field = instr.Operand as FieldDef;
 					if (field == null)
 						continue;
-					if (!MemberReferenceHelper.compareTypes(Method.DeclaringType, field.DeclaringType))
+					if (!new SigComparer().Equals(Method.DeclaringType, field.DeclaringType))
 						continue;
-					switch (field.FieldType.FullName) {
+					switch (field.FieldSig.GetFieldType().GetFullName()) {
 					case "System.Char[]":
 						if (!charArrayFields.Contains(field))
 							charArrayFields.Add(field);
@@ -493,20 +492,20 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				return null;
 			}
 
-			static bool matches(IEnumerable<FieldDef> ourFields, FieldReference field) {
+			static bool matches(IEnumerable<FieldDef> ourFields, FieldDef field) {
 				foreach (var ourField in ourFields) {
-					if (MemberReferenceHelper.compareFieldReferenceAndDeclaringType(ourField, field))
+					if (FieldEqualityComparer.CompareDeclaringTypes.Equals(ourField, field))
 						return true;
 				}
 				return false;
 			}
 
 			short[] findKey() {
-				if (cctor.Module.Assembly == null)
+				if (cctor.OwnerModule.Assembly == null)
 					return null;
-				var pkt = cctor.Module.Assembly.Name.PublicKeyToken;
-				if (pkt != null && pkt.Length > 0)
-					return getPublicKeyTokenKey(pkt);
+				var pkt = cctor.OwnerModule.Assembly.PublicKeyToken;
+				if (!PublicKeyBase.IsNullOrEmpty2(pkt))
+					return getPublicKeyTokenKey(pkt.Data);
 				return findKey(cctor);
 			}
 
@@ -539,7 +538,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 
 			public void cleanup() {
 				encryptedDataField.InitialValue = new byte[1];
-				encryptedDataField.FieldType = encryptedDataField.Module.TypeSystem.Byte;
+				encryptedDataField.FieldSig.Type = encryptedDataField.OwnerModule.CorLibTypes.Byte;
 				removeInitializeArrayCall(cctor, encryptedDataField);
 			}
 		}
@@ -605,9 +604,9 @@ namespace de4dot.code.deobfuscators.DeepSea {
 					var field = instr.Operand as FieldDef;
 					if (field == null)
 						continue;
-					if (!MemberReferenceHelper.compareTypes(Method.DeclaringType, field.DeclaringType))
+					if (!new SigComparer().Equals(Method.DeclaringType, field.DeclaringType))
 						continue;
-					switch (field.FieldType.FullName) {
+					switch (field.FieldSig.GetFieldType().GetFullName()) {
 					case "System.Char[]":
 						if (keyField != null && keyField != field)
 							return false;
@@ -629,11 +628,11 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			}
 
 			short[] findKey() {
-				if (cctor.Module.Assembly == null)
+				if (cctor.OwnerModule.Assembly == null)
 					return null;
-				var pkt = cctor.Module.Assembly.Name.PublicKeyToken;
-				if (pkt != null && pkt.Length > 0)
-					return getPublicKeyTokenKey(pkt);
+				var pkt = cctor.OwnerModule.Assembly.PublicKeyToken;
+				if (!PublicKeyBase.IsNullOrEmpty2(pkt))
+					return getPublicKeyTokenKey(pkt.Data);
 				return findKey(cctor);
 			}
 
@@ -654,14 +653,14 @@ namespace de4dot.code.deobfuscators.DeepSea {
 				var instrs = method.Body.Instructions;
 				for (int i = 0; i < instrs.Count - 2; i++) {
 					var ldarg = instrs[i];
-					if (DotNetUtils.getArgIndex(ldarg) < 0)
+					if (ldarg.GetParameterIndex() < 0)
 						continue;
 					var ldci4 = instrs[i + 1];
-					if (!DotNetUtils.isLdcI4(ldci4))
+					if (!ldci4.IsLdcI4())
 						continue;
 					if (instrs[i + 2].OpCode.Code != Code.Xor)
 						continue;
-					magic = DotNetUtils.getLdcI4Value(ldci4);
+					magic = ldci4.GetLdcI4Value();
 					return true;
 				}
 				magic = 0;
@@ -720,7 +719,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			}
 		}
 
-		public StringDecrypter(ModuleDefinition module) {
+		public StringDecrypter(ModuleDefMD module) {
 			this.module = module;
 		}
 
@@ -728,9 +727,10 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			if (module.Assembly == null)
 				return;
 
-			bool hasPublicKeyToken = module.Assembly.Name.PublicKeyToken != null && module.Assembly.Name.PublicKeyToken.Length != 0;
+			var pkt = module.Assembly.PublicKeyToken;
+			bool hasPublicKeyToken = !PublicKeyBase.IsNullOrEmpty2(pkt);
 			foreach (var type in module.GetTypes()) {
-				var cctor = DotNetUtils.getMethod(type, ".cctor");
+				var cctor = type.FindClassConstructor();
 				if (cctor == null)
 					continue;
 
@@ -777,7 +777,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			foreach (var field in fields) {
 				if (foundCharAry && foundStringAry)
 					break;
-				switch (field.FieldType.FullName) {
+				switch (field.FieldSig.GetFieldType().GetFullName()) {
 				case "System.Char[]":
 					foundCharAry = true;
 					break;
@@ -810,7 +810,7 @@ namespace de4dot.code.deobfuscators.DeepSea {
 			return info;
 		}
 
-		public string decrypt(MethodReference method, object[] args) {
+		public string decrypt(IMethod method, object[] args) {
 			var info = methodToInfo.find(method);
 			return info.decrypt(args);
 		}
diff --git a/de4dot.cui/Program.cs b/de4dot.cui/Program.cs
index 30b5433c..f4b45fef 100644
--- a/de4dot.cui/Program.cs
+++ b/de4dot.cui/Program.cs
@@ -43,9 +43,7 @@ namespace de4dot.cui {
 				new de4dot.code.deobfuscators.CodeVeil.DeobfuscatorInfo(),
 				new de4dot.code.deobfuscators.CodeWall.DeobfuscatorInfo(),
 				new de4dot.code.deobfuscators.CryptoObfuscator.DeobfuscatorInfo(),
-#if PORT
 				new de4dot.code.deobfuscators.DeepSea.DeobfuscatorInfo(),
-#endif
 				new de4dot.code.deobfuscators.Dotfuscator.DeobfuscatorInfo(),
 #if PORT
 				new de4dot.code.deobfuscators.dotNET_Reactor.v3.DeobfuscatorInfo(),
diff --git a/dot10 b/dot10
index ba1fa213..acae785a 160000
--- a/dot10
+++ b/dot10
@@ -1 +1 @@
-Subproject commit ba1fa2135fec435ecee2ea041c9a7dae56e5dd47
+Subproject commit acae785a75c91f9ddabbf6e78d831febcbef16b3