diff --git a/llvm/include/llvm/Assembly/PrintModulePass.h b/llvm/include/llvm/Assembly/PrintModulePass.h
index 1dfb75e049da..a86f13cf7fba 100644
--- a/llvm/include/llvm/Assembly/PrintModulePass.h
+++ b/llvm/include/llvm/Assembly/PrintModulePass.h
@@ -28,7 +28,7 @@ public:
   }
   
   bool run(Module &M) {
-    (*Out) << M;
+    (*Out) << M << std::flush;
     return false;
   }