diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 857b41415ab..44706d7647d 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -877,10 +877,12 @@ DIE *CompileUnit::getOrCreateContextDIE(DIScope Context) {
 /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
 /// given DIType.
 DIE *CompileUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
-  DIType Ty(TyNode);
-  if (!Ty.isType())
+  if (!TyNode)
     return NULL;
 
+  DIType Ty(TyNode);
+  assert(Ty.isType());
+
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE.
   DIE *ContextDIE = getOrCreateContextDIE(resolve(Ty.getContext()));