diff --git a/sisyphus/job.py b/sisyphus/job.py
index dec8615..1d75d6d 100644
--- a/sisyphus/job.py
+++ b/sisyphus/job.py
@@ -497,7 +497,7 @@ def _sis_cleanable(self):
         elif self._sis_cleanable_cache:
             return True
         else:
-            if not os.path.islink(self._sis_path()):
+            if os.path.islink(self._sis_path()):
                 self._sis_cleaned_or_not_cleanable = True
                 return False
             cleanable = not os.path.isfile(self._sis_path(gs.JOB_FINISHED_ARCHIVE)) and self._sis_finished()