diff --git a/PanACoTA/utils.py b/PanACoTA/utils.py
index c03408a0d8b6f38f6da97b02d8da252a5f7d1528..13ca5fdce04ce90ed565f2711ec48b5594d008a6 100755
--- a/PanACoTA/utils.py
+++ b/PanACoTA/utils.py
@@ -305,9 +305,9 @@ def run_cmd(cmd, error, eof=False, **kwargs):
     except OSError:
         logger.error(error + ": " + "{} does not exist".format(cmd))
         if eof:
-            sys.exit(-1)
+            sys.exit(1)
         else:
-            return -1
+            return 1
     if retcode != 0:
         logger.error(error)
         if eof: