DistutilsSetupError was not raised when one single warning occured
diff --git a/Lib/distutils/command/check.py b/Lib/distutils/command/check.py
index d164f3f..7d56dfc 100644
--- a/Lib/distutils/command/check.py
+++ b/Lib/distutils/command/check.py
@@ -72,7 +72,7 @@
 
         # let's raise an error in strict mode, if we have at least
         # one warning
-        if self.strict and self._warnings > 1:
+        if self.strict and self._warnings > 0:
             raise DistutilsSetupError('Please correct your package.')
 
     def check_metadata(self):