diff --git a/include/clang/Basic/DiagnosticFrontendKinds.td b/include/clang/Basic/DiagnosticFrontendKinds.td
index 5a67617..417a22c 100644
--- a/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -107,7 +107,7 @@
     "unknown %0 warning specifier: '%1'">,
     InGroup<DiagGroup<"unknown-warning-option"> >;
 
-def warn_unknown_analyzer_checker : Warning<
+def err_unknown_analyzer_checker : Error<
     "no analyzer checkers are associated with '%0'">;
 def warn_incompatible_analyzer_plugin_api : Warning<
     "checker plugin '%0' is not compatible with this version of the analyzer">,
diff --git a/lib/StaticAnalyzer/Frontend/CheckerRegistration.cpp b/lib/StaticAnalyzer/Frontend/CheckerRegistration.cpp
index c06da0d..0229aed 100644
--- a/lib/StaticAnalyzer/Frontend/CheckerRegistration.cpp
+++ b/lib/StaticAnalyzer/Frontend/CheckerRegistration.cpp
@@ -118,7 +118,7 @@
 
   for (unsigned i = 0, e = checkerOpts.size(); i != e; ++i) {
     if (checkerOpts[i].isUnclaimed())
-      diags.Report(diag::warn_unknown_analyzer_checker)
+      diags.Report(diag::err_unknown_analyzer_checker)
           << checkerOpts[i].getName();
   }
 
diff --git a/test/Misc/warning-flags.c b/test/Misc/warning-flags.c
index f7c23df..a63937b 100644
--- a/test/Misc/warning-flags.c
+++ b/test/Misc/warning-flags.c
@@ -1,4 +1,5 @@
-RUN: diagtool list-warnings | FileCheck %s
+RUN: diagtool list-warnings > %t 2>&1
+RUN: FileCheck --input-file=%t %s
 
 This test serves two purposes:
 
@@ -17,7 +18,7 @@
 
 The list of warnings below should NEVER grow.  It should gradually shrink to 0.
 
-CHECK: Warnings without flags (131):
+CHECK: Warnings without flags (130):
 CHECK-NEXT:   pp_include_next_absolute_path
 CHECK-NEXT:   pp_include_next_in_primary
 CHECK-NEXT:   pp_invalid_string_literal
@@ -144,7 +145,6 @@
 CHECK-NEXT:   warn_undef_interface_suggest
 CHECK-NEXT:   warn_undef_protocolref
 CHECK-NEXT:   warn_undefined_internal
-CHECK-NEXT:   warn_unknown_analyzer_checker
 CHECK-NEXT:   warn_unknown_method_family
 CHECK-NEXT:   warn_use_out_of_scope_declaration
 CHECK-NEXT:   warn_weak_identifier_undeclared