diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp
index e55b726..ae20e68 100644
--- a/lib/Target/X86/X86MCInstLower.cpp
+++ b/lib/Target/X86/X86MCInstLower.cpp
@@ -515,6 +515,12 @@
     }
     return;
 
+  // Emit nothing here but a comment if we can.
+  case X86::Int_MemBarrier:
+    if (OutStreamer.hasRawTextSupport())
+      OutStreamer.EmitRawText(StringRef("\t#MEMBARRIER"));
+    return;
+        
   case X86::TAILJMPr:
   case X86::TAILJMPd:
   case X86::TAILJMPd64: