always allow -1 as a uid
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index a06ebd1..65ade9f 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -397,8 +397,6 @@
                     goto OverflowUp;
                 return 0;
             }
-            if ((uid_t)uresult == (uid_t)-1)
-                goto OverflowUp;
         } else {
             if (result < 0)
                 goto OverflowDown;
@@ -451,8 +449,6 @@
                     goto OverflowUp;
                 return 0;
             }
-            if ((gid_t)uresult == (gid_t)-1)
-                goto OverflowUp;
         } else {
             if (result < 0)
                 goto OverflowDown;