diff --git a/rc.lua b/rc.lua
index 689e2a8..15db837 100644
--- a/rc.lua
+++ b/rc.lua
@@ -389,7 +389,7 @@ globalkeys = gears.table.join(
 )
 
 clientkeys = gears.table.join(
-	awful.key({ modkey }, "f", function(c)
+	awful.key({ mod4, modkey }, "f", function(c)
 		c.fullscreen = not c.fullscreen
 		c:raise()
 	end, { description = "toggle fullscreen", group = "client" }),