diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 1f733be..784e018 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1798,7 +1798,7 @@
     else if (CXXDecl->isDynamicClass())
       ContainingType = RealDecl;
 
-    RealDecl->replaceOperandWith(9, ContainingType);
+    RealDecl->replaceOperandWith(12, ContainingType);
   }
   return llvm::DIType(RealDecl);
 }