--- a/testing/geckodriver/src/marionette.rs
+++ b/testing/geckodriver/src/marionette.rs
@@ -1049,17 +1049,17 @@ impl MarionetteCommand {
             GetWindowHandles => (Some("getWindowHandles"), None),
             CloseWindow => (Some("close"), None),
             GetTimeouts => (Some("getTimeouts"), None),
             SetTimeouts(ref x) => (Some("setTimeouts"), Some(x.to_marionette())),
             SetWindowRect(ref x) => (Some("setWindowRect"), Some(x.to_marionette())),
             GetWindowRect => (Some("getWindowRect"), None),
             MinimizeWindow => (Some("WebDriver:MinimizeWindow"), None),
             MaximizeWindow => (Some("maximizeWindow"), None),
-            FullscreenWindow => (Some("fullscreenWindow"), None),
+            FullscreenWindow => (Some("fullscreen"), None),
             SwitchToWindow(ref x) => (Some("switchToWindow"), Some(x.to_marionette())),
             SwitchToFrame(ref x) => (Some("switchToFrame"), Some(x.to_marionette())),
             SwitchToParentFrame => (Some("switchToParentFrame"), None),
             FindElement(ref x) => (Some("findElement"), Some(x.to_marionette())),
             FindElements(ref x) => (Some("findElements"), Some(x.to_marionette())),
             FindElementElement(ref e, ref x) => {
                 let mut data = try!(x.to_marionette());
                 data.insert("element".to_string(), e.id.to_json());