#6954: Fixed crash when using DISTUTILS_DEBUG flag in Distutils.
diff --git a/Lib/distutils/log.py b/Lib/distutils/log.py
index 6f949d5..7588570 100644
--- a/Lib/distutils/log.py
+++ b/Lib/distutils/log.py
@@ -17,6 +17,9 @@
         self.threshold = threshold
 
     def _log(self, level, msg, args):
+        if level not in (DEBUG, INFO, WARN, ERROR, FATAL):
+            raise ValueError('%s wrong log level' % str(level))
+
         if level >= self.threshold:
             if args:
                 msg = msg % args