diff --git a/ICSharpCode.Decompiler.Tests/TestCases/Correctness/InitializerTests.cs b/ICSharpCode.Decompiler.Tests/TestCases/Correctness/InitializerTests.cs
index 393fa9374..c975fa00a 100644
--- a/ICSharpCode.Decompiler.Tests/TestCases/Correctness/InitializerTests.cs
+++ b/ICSharpCode.Decompiler.Tests/TestCases/Correctness/InitializerTests.cs
@@ -1015,5 +1015,35 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Correctness
 			}
 		};
 		}
+
+		class Issue855
+		{
+			class Data
+			{
+				public object Obj;
+			}
+
+			class Items
+			{
+				public void SetItem(int i, object item) { }
+			}
+
+			object Item(string s, Data d)
+			{
+				return new object();
+			}
+
+			void Test()
+			{
+				Items items = null;
+
+				int num = 0;
+
+				for (int i = 0; i < 2; i++) {
+					if (num < 10)
+						items.SetItem(num, Item(string.Empty, new Data { Obj = null }));
+				}
+			}
+		}
 	}
 }
\ No newline at end of file
diff --git a/ICSharpCode.Decompiler/IL/Transforms/LockTransform.cs b/ICSharpCode.Decompiler/IL/Transforms/LockTransform.cs
index cbc06bbb3..1aa31130d 100644
--- a/ICSharpCode.Decompiler/IL/Transforms/LockTransform.cs
+++ b/ICSharpCode.Decompiler/IL/Transforms/LockTransform.cs
@@ -22,7 +22,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				// This happens in some cases:
 				// Use correct index after transformation.
 				if (i >= block.Instructions.Count)
-					i = block.Instructions.Count - 1;
+					i = block.Instructions.Count;
 			}
 		}
 
diff --git a/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs b/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
index 6b28ac2f5..3e6f175f2 100644
--- a/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
+++ b/ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
@@ -36,6 +36,10 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			for (int i = block.Instructions.Count - 1; i >= 0; i--)
 			{
 				DoTransform(block, i);
+				// This happens in some cases:
+				// Use correct index after transformation.
+				if (i >= block.Instructions.Count)
+					i = block.Instructions.Count;
 			}
 		}