diff --git a/picoscope/picobase.py b/picoscope/picobase.py
index e02d788..00299fb 100644
--- a/picoscope/picobase.py
+++ b/picoscope/picobase.py
@@ -1127,7 +1127,7 @@ def close(self):
         You should call this yourself because the Python garbage collector
         might take some time.
         """
-        if self.handle is not None:
+        if self.handle:
             self._lowLevelCloseUnit()
             self.handle = None