diff --git a/clang/include/clang/Basic/DiagnosticIDs.h b/clang/include/clang/Basic/DiagnosticIDs.h
index 6dd78bf93eaab..a59ff25fe20eb 100644
--- a/clang/include/clang/Basic/DiagnosticIDs.h
+++ b/clang/include/clang/Basic/DiagnosticIDs.h
@@ -36,7 +36,7 @@ namespace clang {
       DIAG_SIZE_SERIALIZATION =  120,
       DIAG_SIZE_LEX           =  400,
       DIAG_SIZE_PARSE         =  700,
-      DIAG_SIZE_AST           =  250,
+      DIAG_SIZE_AST           =  300,
       DIAG_SIZE_COMMENT       =  100,
       DIAG_SIZE_CROSSTU       =  100,
       DIAG_SIZE_SEMA          = 4500,