diff --git a/blocks/BaseBlock.cs b/blocks/BaseBlock.cs
index 622c46bf..23a2f79b 100644
--- a/blocks/BaseBlock.cs
+++ b/blocks/BaseBlock.cs
@@ -19,9 +19,9 @@
 
 namespace de4dot.blocks {
 	public abstract class BaseBlock {
-		BaseBlock parent = null;
+		ScopeBlock parent = null;
 
-		public BaseBlock Parent {
+		public ScopeBlock Parent {
 			get { return parent; }
 			set { parent = value; }
 		}
diff --git a/blocks/Blocks.cs b/blocks/Blocks.cs
index 9e00a6f2..681de1b0 100644
--- a/blocks/Blocks.cs
+++ b/blocks/Blocks.cs
@@ -235,16 +235,14 @@ namespace de4dot.blocks {
 					break;
 			}
 
-			foreach (var nopBlock in nopBlocks.Keys) {
-				var scopeBlock = (ScopeBlock)nopBlock.Parent;
-				scopeBlock.removeDeadBlock(nopBlock);
-			}
+			foreach (var nopBlock in nopBlocks.Keys)
+				nopBlock.Parent.removeDeadBlock(nopBlock);
 		}
 
 		static Block getNopBlockTarget(Dictionary<Block, bool> nopBlocks, Block source, Block nopBlock) {
 			if (nopBlock == null || !nopBlocks.ContainsKey(nopBlock) || source == nopBlock.FallThrough)
 				return null;
-			if (((ScopeBlock)nopBlock.Parent).BaseBlocks[0] == nopBlock)
+			if (nopBlock.Parent.BaseBlocks[0] == nopBlock)
 				return null;
 			var target = nopBlock.FallThrough;
 			if (nopBlock.Parent != target.Parent)
diff --git a/blocks/DeadBlocksRemover.cs b/blocks/DeadBlocksRemover.cs
index 1fc8e743..aaac1f4c 100644
--- a/blocks/DeadBlocksRemover.cs
+++ b/blocks/DeadBlocksRemover.cs
@@ -53,7 +53,7 @@ namespace de4dot.blocks {
 			var deadBlocksDict = new Dictionary<BaseBlock, bool>();
 			foreach (var baseBlock in findDeadBlocks()) {
 				deadBlocksDict[baseBlock] = true;
-				ScopeBlock parent = (ScopeBlock)baseBlock.Parent;
+				ScopeBlock parent = baseBlock.Parent;
 				ScopeBlockInfo info;
 				if (!infos.TryGetValue(parent, out info))
 					infos[parent] = info = new ScopeBlockInfo(parent);
diff --git a/blocks/InstructionListParser.cs b/blocks/InstructionListParser.cs
index 6ba1f3ef..7ff72578 100644
--- a/blocks/InstructionListParser.cs
+++ b/blocks/InstructionListParser.cs
@@ -282,7 +282,7 @@ namespace de4dot.blocks {
 			}
 
 			// Replace the BaseBlocks with a new BaseBlock, returning the old ones.
-			public List<BaseBlock> replace(int startInstr, int endInstr, BaseBlock bb) {
+			public List<BaseBlock> replace(int startInstr, int endInstr, ScopeBlock bb) {
 				int startIndex, endIndex;
 				var rv = getBlocks(startInstr, endInstr, out startIndex, out endIndex);
 				updateParent(rv, bb);
@@ -294,7 +294,7 @@ namespace de4dot.blocks {
 				return rv;
 			}
 
-			public List<BaseBlock> getBlocks(BaseBlock parent) {
+			public List<BaseBlock> getBlocks(ScopeBlock parent) {
 				if (blocksLeft.Count == 0)
 					return new List<BaseBlock>();
 				int startIndex, endIndex;
@@ -302,7 +302,7 @@ namespace de4dot.blocks {
 				return updateParent(lb, parent);
 			}
 
-			List<BaseBlock> updateParent(List<BaseBlock> lb, BaseBlock parent) {
+			List<BaseBlock> updateParent(List<BaseBlock> lb, ScopeBlock parent) {
 				foreach (var bb in lb)
 					bb.Parent = parent;
 				return lb;
diff --git a/blocks/ScopeBlock.cs b/blocks/ScopeBlock.cs
index bb227e00..53996920 100644
--- a/blocks/ScopeBlock.cs
+++ b/blocks/ScopeBlock.cs
@@ -174,10 +174,7 @@ namespace de4dot.blocks {
 			if (isOurBaseBlock(bb))
 				return bb;
 
-			for (bb = bb.Parent; bb != null; bb = bb.Parent) {
-				var sb = bb as ScopeBlock;
-				if (sb == null)
-					throw new ApplicationException("Parent is not a ScopeBlock");
+			for (var sb = bb.Parent; sb != null; sb = sb.Parent) {
 				if (isOurBaseBlock(sb))
 					return sb;
 			}
diff --git a/de4dot.code/deobfuscators/SmartAssembly/TamperProtectionRemover.cs b/de4dot.code/deobfuscators/SmartAssembly/TamperProtectionRemover.cs
index e64ad353..b6588e38 100644
--- a/de4dot.code/deobfuscators/SmartAssembly/TamperProtectionRemover.cs
+++ b/de4dot.code/deobfuscators/SmartAssembly/TamperProtectionRemover.cs
@@ -348,7 +348,7 @@ namespace de4dot.code.deobfuscators.SmartAssembly {
 		}
 
 		void removeDeadBlock(Block block) {
-			var parent = (ScopeBlock)block.Parent;
+			var parent = block.Parent;
 			if (parent != null)	// null if already dead
 				parent.removeDeadBlock(block);
 		}
diff --git a/de4dot.code/deobfuscators/dotNET_Reactor/AntiStrongname.cs b/de4dot.code/deobfuscators/dotNET_Reactor/AntiStrongname.cs
index 4c2cd10b..5915c097 100644
--- a/de4dot.code/deobfuscators/dotNET_Reactor/AntiStrongname.cs
+++ b/de4dot.code/deobfuscators/dotNET_Reactor/AntiStrongname.cs
@@ -99,15 +99,15 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor {
 			antiSnBlock.replaceLastInstrsWithBranch(numInstructions, goodBlock);
 
 			if (badBlock.FallThrough == badBlock && badBlock.Sources.Count == 1 && badBlock.Targets == null) {
-				((ScopeBlock)badBlock.Parent).removeGuaranteedDeadBlock(badBlock);
+				badBlock.Parent.removeGuaranteedDeadBlock(badBlock);
 				return true;
 			}
 			if (badBlock.Instructions.Count <= 1 && badBlock.LastInstr.OpCode.Code == Code.Nop) {
 				if (badBlock.FallThrough != null && badBlock.Targets == null && badBlock.Sources.Count == 0) {
 					var badBlock2 = badBlock.FallThrough;
 					if (badBlock2.FallThrough == badBlock2 && badBlock2.Sources.Count == 2 && badBlock2.Targets == null) {
-						((ScopeBlock)badBlock.Parent).removeGuaranteedDeadBlock(badBlock);
-						((ScopeBlock)badBlock2.Parent).removeGuaranteedDeadBlock(badBlock2);
+						badBlock.Parent.removeGuaranteedDeadBlock(badBlock);
+						badBlock2.Parent.removeGuaranteedDeadBlock(badBlock2);
 						return true;
 					}
 				}