diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index e1dca0e..1bd0918 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -752,10 +752,13 @@
     return llvm::DIType();
 
   // Check for existing entry.
-  std::map<void *, llvm::AssertingVH<llvm::MDNode> >::iterator it =
+  std::map<void *, llvm::WeakVH>::iterator it =
     TypeCache.find(Ty.getAsOpaquePtr());
-  if (it != TypeCache.end())
-    return llvm::DIType(it->second);
+  if (it != TypeCache.end()) {
+    // Verify that the debug info still exists.
+    if (&*it->second)
+      return llvm::DIType(cast<llvm::MDNode>(it->second));
+  }
 
   // Otherwise create the type.
   llvm::DIType Res = CreateTypeNode(Ty, Unit);
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index d0f0731..b796b1e 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -49,7 +49,7 @@
 
   /// TypeCache - Cache of previously constructed Types.
   // FIXME: Eliminate this map.  Be careful of iterator invalidation.
-  std::map<void *, llvm::AssertingVH<llvm::MDNode> > TypeCache;
+  std::map<void *, llvm::WeakVH> TypeCache;
 
   bool BlockLiteralGenericSet;
   llvm::DIType BlockLiteralGeneric;