diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 4c24d03..6def967 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -411,7 +411,7 @@
       = SLocEntry::get(Offset, FileInfo::get(IncludePos, File, FileCharacter));
     SLocEntryLoaded[PreallocatedID] = true;
     FileID FID = FileID::get(PreallocatedID);
-    return LastFileIDLookup = FID;
+    return FID;
   }
 
   SLocEntryTable.push_back(SLocEntry::get(NextOffset,