diff --git a/clang/include/clang/Basic/DiagnosticIDs.h b/clang/include/clang/Basic/DiagnosticIDs.h
index bf4995175ef19..06ef1c6904c31 100644
--- a/clang/include/clang/Basic/DiagnosticIDs.h
+++ b/clang/include/clang/Basic/DiagnosticIDs.h
@@ -31,7 +31,7 @@ namespace clang {
     // Size of each of the diagnostic categories.
     enum {
       DIAG_SIZE_COMMON        =  300,
-      DIAG_SIZE_DRIVER        =  300,
+      DIAG_SIZE_DRIVER        =  400,
       DIAG_SIZE_FRONTEND      =  150,
       DIAG_SIZE_SERIALIZATION =  120,
       DIAG_SIZE_LEX           =  400,