diff --git a/src/sniffles/utils/resmon.py b/src/sniffles/utils/resmon.py
index 0bd86db..8092ddf 100644
--- a/src/sniffles/utils/resmon.py
+++ b/src/sniffles/utils/resmon.py
@@ -48,9 +48,10 @@ def __init__(self, config: SnifflesConfig):
 
         try:
             from psutil import Process
-        except ImportError as ex:
+        except ImportError:
             logging.getLogger('sniffles.dependencies').warning(f'Dependency psutil not available - resource monitoring is disabled.')
             self._process = None
+            self._workers = {}
         else:
             self._process = Process(self._pid)