diff --git a/DFReader.py b/DFReader.py
index e442d10c2..ee9c773b1 100644
--- a/DFReader.py
+++ b/DFReader.py
@@ -619,7 +619,7 @@ def metadata_tree(self,verbose=False):
     def print_help(self,msg):
         '''print help for a log message'''
         data = self.metadata_tree(verbose=True)
-        if data is None or not msg in data:
+        if data is None or msg not in data:
             return
         node = data[msg]
         # Message name and description