diff --git a/lib/IR/Metadata.cpp b/lib/IR/Metadata.cpp
index 150a186424c..cd5edd216c3 100644
--- a/lib/IR/Metadata.cpp
+++ b/lib/IR/Metadata.cpp
@@ -341,7 +341,8 @@ MDString *MDString::get(LLVMContext &Context, StringRef Str) {
   if (I != Store.end())
     return &I->second;
 
-  auto *Entry = StringMapEntry<MDString>::Create(Str, Store.getAllocator());
+  auto *Entry =
+      StringMapEntry<MDString>::Create(Str, Store.getAllocator(), MDString());
   bool WasInserted = Store.insert(Entry);
   (void)WasInserted;
   assert(WasInserted && "Expected entry to be inserted");