diff --git a/source/_docs/z-wave/installation.markdown b/source/_docs/z-wave/installation.markdown
index 6a9693fddf9..9bd27a789e2 100644
--- a/source/_docs/z-wave/installation.markdown
+++ b/source/_docs/z-wave/installation.markdown
@@ -148,7 +148,7 @@ $ dmesg | grep USB
 If Home Assistant (`hass`) runs with another user (e.g., *homeassistant* on Hassbian) give access to the stick with:
 
 ```bash
-$ sudo usermod -a -G dialout homeassistant
+$ sudo usermod -aG dialout homeassistant
 ```
 
 <p class='Note'>