--- a/memory/mozalloc/throw_gcc.h
+++ b/memory/mozalloc/throw_gcc.h
@@ -133,13 +133,22 @@ MOZ_THROW_NORETURN MOZ_EXPORT MOZ_ALWAYS
 __throw_system_error(int err)
 {
     char error[128];
     snprintf(error, sizeof(error)-1,
              "fatal: STL threw system_error: %s (%d)", strerror(err), err);
     mozalloc_abort(error);
 }
 
+MOZ_THROW_NORETURN MOZ_EXPORT MOZ_ALWAYS_INLINE void
+__throw_regex_error(int __ecode)
+{
+    char error[128];
+    snprintf(error, sizeof(error)-1,
+             "fatal: STL threw regex_error(%d)", __ecode);
+    mozalloc_abort(error);
+}
+
 } // namespace std
 
 #undef MOZ_THROW_NORETURN
 
 #endif  // mozilla_throw_gcc_h