diff --git a/de4dot.blocks/GenericArgsSubstitutor.cs b/de4dot.blocks/GenericArgsSubstitutor.cs
index 17d83e66..77e6b95a 100644
--- a/de4dot.blocks/GenericArgsSubstitutor.cs
+++ b/de4dot.blocks/GenericArgsSubstitutor.cs
@@ -19,6 +19,7 @@
 
 using System.Collections.Generic;
 using dnlib.DotNet;
+using dnlib.Threading;
 
 namespace de4dot.blocks {
 	public struct GenericArgsSubstitutor {
@@ -291,7 +292,7 @@ namespace de4dot.blocks {
 				newSig.Params.Add(Create2(sig.Params[i]));
 			newSig.GenParamCount = sig.GenParamCount;
 			if (sig.ParamsAfterSentinel != null) {
-				newSig.ParamsAfterSentinel = new List<TypeSig>();
+				newSig.ParamsAfterSentinel = ThreadSafeListCreator.Create<TypeSig>();
 				for (int i = 0; i < sig.ParamsAfterSentinel.Count; i++)
 					newSig.ParamsAfterSentinel.Add(Create2(sig.ParamsAfterSentinel[i]));
 			}
diff --git a/de4dot.code/DumpedMethodsRestorer.cs b/de4dot.code/DumpedMethodsRestorer.cs
index ffd17f25..b4852164 100644
--- a/de4dot.code/DumpedMethodsRestorer.cs
+++ b/de4dot.code/DumpedMethodsRestorer.cs
@@ -61,15 +61,14 @@ namespace de4dot.code {
 			return false;
 		}
 
-		public bool HasMethodBody(uint rid) {
-			return GetDumpedMethod(rid) != null;
-		}
-
-		public MethodBody GetMethodBody(uint rid, RVA rva, IList<Parameter> parameters) {
+		public bool GetMethodBody(uint rid, RVA rva, IList<Parameter> parameters, out MethodBody methodBody) {
 			var dm = GetDumpedMethod(rid);
-			if (dm == null)
-				return null;
-			return MethodBodyReader.CreateCilBody(module, dm.code, dm.extraSections, parameters, dm.mhFlags, dm.mhMaxStack, dm.mhCodeSize, dm.mhLocalVarSigTok);
+			if (dm == null) {
+				methodBody = null;
+				return false;
+			}
+			methodBody = MethodBodyReader.CreateCilBody(module, dm.code, dm.extraSections, parameters, dm.mhFlags, dm.mhMaxStack, dm.mhCodeSize, dm.mhLocalVarSigTok);
+			return true;
 		}
 	}
 }