diff --git a/src/IKVM.ByteCode/Decoding/StackMapFrame.cs b/src/IKVM.ByteCode/Decoding/StackMapFrame.cs
index ee2ff56..a045624 100644
--- a/src/IKVM.ByteCode/Decoding/StackMapFrame.cs
+++ b/src/IKVM.ByteCode/Decoding/StackMapFrame.cs
@@ -217,7 +217,7 @@ public readonly void CopyTo<TConstantView, TConstantPool>(TConstantView constant
             where TConstantView : IConstantView
             where TConstantPool : IConstantPool
         {
-            if (FrameType is <= 65)
+            if (FrameType is <= 63)
                 ((SameStackMapFrame)this).CopyTo(constantView, constantPool, ref encoder);
             else if (FrameType is >= 64 and <= 127)
                 ((SameLocalsOneStackMapFrame)this).CopyTo(constantView, constantPool, ref encoder);