diff --git a/llvm/lib/Support/DataStream.cpp b/llvm/lib/Support/DataStream.cpp
index 1caeddf..cb36d9c 100644
--- a/llvm/lib/Support/DataStream.cpp
+++ b/llvm/lib/Support/DataStream.cpp
@@ -83,7 +83,7 @@
   if (error_code e = s->OpenFile(Filename)) {
     *StrError = std::string("Could not open ") + Filename + ": " +
         e.message() + "\n";
-    return NULL;
+    return nullptr;
   }
   return s;
 }