diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index fa59212..f6ba4e5 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -561,6 +561,7 @@
   Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
   Opts.ElideType = !Args.hasArg(OPT_fno_elide_type);
   Opts.ShowTemplateTree = Args.hasArg(OPT_fdiagnostics_show_template_tree);
+  Opts.WarnOnSpellCheck = Args.hasArg(OPT_fwarn_on_spellcheck);
   Opts.ErrorLimit = Args.getLastArgIntValue(OPT_ferror_limit, 0, Diags);
   Opts.MacroBacktraceLimit
     = Args.getLastArgIntValue(OPT_fmacro_backtrace_limit,
diff --git a/lib/Frontend/Warnings.cpp b/lib/Frontend/Warnings.cpp
index 767096a..b7547b9 100644
--- a/lib/Frontend/Warnings.cpp
+++ b/lib/Frontend/Warnings.cpp
@@ -56,6 +56,7 @@
 
   Diags.setElideType(Opts.ElideType);
   Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
+  Diags.setWarnOnSpellCheck(Opts.WarnOnSpellCheck);
   Diags.setShowColors(Opts.ShowColors);
  
   // Handle -ferror-limit
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 86ddad2..ad5b89a 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -3738,11 +3738,12 @@
   if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
     return TypoCorrection();
 
-  // This is for regression testing. It's disabled by default.
-  if (Diags.getDiagnosticLevel(diag::warn_spellcheck_initiated,
-                               TypoName.getLoc()) != DiagnosticsEngine::Ignored)
-    Diag(TypoName.getLoc(), diag::warn_spellcheck_initiated)
-      << TypoName.getName();
+  // This is for testing.
+  if (Diags.getWarnOnSpellCheck()) {
+    unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Warning,
+                                            "spell-checking initiated for %0");
+    Diag(TypoName.getLoc(), DiagID) << TypoName.getName();
+  }
 
   NamespaceSpecifierSet Namespaces(Context, CurContext, SS);