diff --git a/lib/Bytecode/Reader/ReaderInternals.h b/lib/Bytecode/Reader/ReaderInternals.h
index a57ad7cf049..9044c0f6c58 100644
--- a/lib/Bytecode/Reader/ReaderInternals.h
+++ b/lib/Bytecode/Reader/ReaderInternals.h
@@ -15,7 +15,7 @@
 #include <map>
 
 // Enable to trace to figure out what the heck is going on when parsing fails
-#define TRACE_LEVEL 0
+//#define TRACE_LEVEL 10
 
 #if TRACE_LEVEL    // ByteCodeReading_TRACEer
 #define BCR_TRACE(n, X) \