diff --git a/doc/man/gdctl.rst b/doc/man/gdctl.rst
index f0f8c4e59..b3f2a83e4 100644
--- a/doc/man/gdctl.rst
+++ b/doc/man/gdctl.rst
@@ -138,7 +138,7 @@ LOGICAL MONITOR OPTIONS
 MONITOR OPTIONS
 ---------------
 
-``--mode``, ``-M``
+``--mode``, ``-m``
 
   Set the mode of the monitor.