diff --git a/test/libcxx/input.output/file.streams/fstreams/traits_mismatch.fail.cpp b/test/libcxx/input.output/file.streams/fstreams/traits_mismatch.fail.cpp
index dcb7b1f64..c843b7e98 100644
--- a/test/libcxx/input.output/file.streams/fstreams/traits_mismatch.fail.cpp
+++ b/test/libcxx/input.output/file.streams/fstreams/traits_mismatch.fail.cpp
@@ -21,5 +21,10 @@ int main()
 	std::basic_fstream<char, std::char_traits<wchar_t> > f;
 //  expected-error-re@ios:* {{static_assert failed{{.*}} "traits_type::char_type must be the same type as CharT"}}
 //  expected-error-re@streambuf:* {{static_assert failed{{.*}} "traits_type::char_type must be the same type as CharT"}}
+
+// FIXME: As of commit r324062 Clang incorrectly generates a diagnostic about mismatching
+// exception specifications for types which are already invalid for one reason or another.
+// For now we tolerate this diagnostic.
+// expected-error@ostream:* 0-1 {{exception specification of overriding function is more lax than base version}}
 }