diff --git a/lib/AST/APValue.cpp b/lib/AST/APValue.cpp
index 50a6e0a..731d5e0 100644
--- a/lib/AST/APValue.cpp
+++ b/lib/AST/APValue.cpp
@@ -48,7 +48,8 @@
   else if (isFloat())
     setFloat(RHS.getFloat());
   else if (isVector())
-    setVector(((Vec*)(char*)RHS.Data)->Elts, RHS.getVectorLength());
+    setVector(((const Vec *)(const char *)RHS.Data)->Elts,
+              RHS.getVectorLength());
   else if (isComplexInt())
     setComplexInt(RHS.getComplexIntReal(), RHS.getComplexIntImag());
   else if (isComplexFloat())