diff --git a/de4dot.code/deobfuscators/MethodCallRestorerBase.cs b/de4dot.code/deobfuscators/MethodCallRestorerBase.cs
index c841f897..48ff3833 100644
--- a/de4dot.code/deobfuscators/MethodCallRestorerBase.cs
+++ b/de4dot.code/deobfuscators/MethodCallRestorerBase.cs
@@ -100,6 +100,8 @@ namespace de4dot.code.deobfuscators {
 		}
 
 		public void deobfuscate(Blocks blocks) {
+			if (oldToNewMethod.Count == 0)
+				return;
 			foreach (var block in blocks.MethodBlocks.getAllBlocks()) {
 				var instrs = block.Instructions;
 				for (int i = 0; i < instrs.Count; i++) {