Index: lib/Support/Windows/Signals.inc
===================================================================
--- lib/Support/Windows/Signals.inc
+++ lib/Support/Windows/Signals.inc
@@ -275,12 +275,15 @@
   // Crash to stack trace handler on abort.
   signal(SIGABRT, HandleAbort);
 
-  // The following functions are not reliably accessible on MinGW.
-#ifdef _MSC_VER
+  // The following functions are only available on MinGW if a sufficiently
+  // current MSVCRT is used (the corresponding runtimes must be installed).
+#if defined(_MSC_VER) || __MSVCRT_VERSION__ >= 0x900
   // We're already handling writing a "something went wrong" message.
   _set_abort_behavior(0, _WRITE_ABORT_MSG);
   // Disable Dr. Watson.
   _set_abort_behavior(0, _CALL_REPORTFAULT);
+#endif
+#ifdef _MSC_VER
   _CrtSetReportHook(AvoidMessageBoxHook);
 #endif