diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 65da264b..34c8383 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1201,4 +1201,7 @@
   
   // Write the generated bitstream to "Out".
   Out.write((char*)&Buffer.front(), Buffer.size());
+  
+  // Make sure it hits disk now.
+  Out.flush();
 }