diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 842bacb..4a5b191 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -48,6 +48,7 @@
   AllExtensionsSilenced = 0;
   IgnoreAllWarnings = false;
   WarningsAsErrors = false;
+  WarnOnSpellCheck = false;
   EnableAllWarnings = false;
   ErrorsAsFatal = false;
   SuppressSystemWarnings = false;