diff --git a/modbus/README.md b/modbus/README.md
index 8463788..c854b01 100644
--- a/modbus/README.md
+++ b/modbus/README.md
@@ -59,7 +59,7 @@
 
 ```
 
-## monitor multiple.py
+## monitor_multiple.py
 ```
 $> python monitor_muiltiple.py -h
 usage: monitor_muiltiple.py [-h] [-co [COIL [COIL ...]]]