diff --git a/scripts/install b/scripts/install
index ceccbbb..aae380f 100755
--- a/scripts/install
+++ b/scripts/install
@@ -120,7 +120,7 @@ ynh_script_progression --message="Configuring system user..." --weight=1
 # Create a system user
 ynh_system_user_create --username=$app
 #allow user to access USB / serial port to communicate with tools (RFXtrx, Z-wave dongle, etc.) & i2c bus
-usermod -a -G dialout i2c $app
+usermod -a -G dialout i2c gpio $app
 
 #allow app user to restart service on startup
 cp ../conf/sudoer ../conf/$app.conf
diff --git a/scripts/restore b/scripts/restore
index 7869b0a..3f94d66 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -92,7 +92,7 @@ ynh_restore_file --origin_path="/etc/sudoers.d/$app"
 #Both folder and database file must be own by app user for domoticz to work and allow internal upgrade
 chown -R $app: $final_path
 #allow user to access USB / serial port to communicate with tools (RFXtrx, Z-wave dongle, etc.) & i2c bus
-usermod -a -G dialout i2c $app
+usermod -a -G dialout i2c gpio $app
 
 
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 557d845..bc938ee 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -175,7 +175,7 @@ ynh_script_progression --message="Making sure dedicated system user exists..."
 # Create a dedicated user (if not existing)
 ynh_system_user_create --username=$app
 #allow user to access USB / serial port to communicate with tools (RFXtrx, Z-wave dongle, etc.) & i2c bus
-usermod -a -G dialout i2c $app
+usermod -a -G dialout i2c gpio $app
 
 #allow app user to restart service on startup
 cp ../conf/sudoer ../conf/$app.conf