diff --git a/src/tools/flow_control.py b/src/tools/flow_control.py
index 08eec97..d5436f1 100755
--- a/src/tools/flow_control.py
+++ b/src/tools/flow_control.py
@@ -189,6 +189,8 @@ class Flow:
 if __name__ == "__main__":
     """
     This is the command line program to control the red-y flow control series.
+    Usage: ./flow_control.py [any number]
+
     """
     conf = os.path.expanduser('~/.flow')
     if os.path.exists(conf):