diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 31c7e14..69b6be7 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -1047,6 +1047,7 @@
   // FIXME: Should there be a way to "include" memory buffers in the translation
   // unit ?
   assert((LEntry != 0 || REntry != 0) && "Locations in memory buffers.");
+  (void) REntry;
   
   // Consider the memory buffer as coming before the file in the translation
   // unit.