diff --git a/testing/geckodriver/src/marionette.rs b/testing/geckodriver/src/marionette.rs
index 363d9ea046c7..b5ff1819c8ef 100644
--- a/testing/geckodriver/src/marionette.rs
+++ b/testing/geckodriver/src/marionette.rs
@@ -40,8 +40,9 @@ use webdriver::command::{
     SwitchToFrameParameters, LocatorParameters, JavascriptCommandParameters,
     GetNamedCookieParameters, AddCookieParameters, TimeoutsParameters,
     ActionsParameters, TakeScreenshotParameters};
-use webdriver::response::{CloseWindowResponse, Cookie, CookieResponse, RectResponse,
-                          NewSessionResponse, TimeoutsResponse, ValueResponse, WebDriverResponse};
+use webdriver::response::{CloseWindowResponse, Cookie, CookieResponse, ElementRectResponse,
+                          NewSessionResponse, TimeoutsResponse, ValueResponse, WebDriverResponse,
+                          WindowRectResponse};
 use webdriver::common::{
     Date, Nullable, WebElement, FrameId, ELEMENT_KEY};
 use webdriver::error::{ErrorStatus, WebDriverError, WebDriverResult};
@@ -636,7 +637,7 @@ impl MarionetteSession {
         Ok(match msg.command {
             // Everything that doesn't have a response value
             Get(_) | GoBack | GoForward | Refresh | SetTimeouts(_) |
-            SwitchToWindow(_) | SwitchToFrame(_) |
+            MaximizeWindow | SwitchToWindow(_) | SwitchToFrame(_) |
             SwitchToParentFrame | AddCookie(_) | DeleteCookies | DeleteCookie(_) |
             DismissAlert | AcceptAlert | SendAlertText(_) | ElementClick(_) |
             ElementTap(_) | ElementClear(_) | ElementSendKeys(_, _) |
@@ -703,6 +704,40 @@ impl MarionetteSession {
                                             })
                                        .collect());
                 WebDriverResponse::CloseWindow(CloseWindowResponse { window_handles: handles })
+            }
+            GetWindowRect => {
+                let width = try_opt!(
+                    try_opt!(resp.result.find("width"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find width field").as_u64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret width as integer");
+
+                let height = try_opt!(
+                    try_opt!(resp.result.find("height"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find height field").as_u64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret width as integer");
+
+                let x = try_opt!(
+                    try_opt!(resp.result.find("x"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find x field").as_i64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret x as integer");
+
+                let y = try_opt!(
+                    try_opt!(resp.result.find("y"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find y field").as_i64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret y as integer");
+
+                WebDriverResponse::WindowRect(WindowRectResponse {x: x,
+                                                                  y: y,
+                                                                  width: width,
+                                                                  height: height})
             },
             GetElementRect(_) => {
                 let x = try_opt!(
@@ -733,10 +768,40 @@ impl MarionetteSession {
                     ErrorStatus::UnknownError,
                     "Failed to interpret width as float");
 
-                WebDriverResponse::ElementRect(RectResponse::new(x, y, width, height))
+                WebDriverResponse::ElementRect(ElementRectResponse::new(x, y, width, height))
             },
-            FullscreenWindow | MaximizeWindow | GetWindowRect |
-            MaximizeWindow | SetWindowRect(_) => {
+            SetWindowRect(_) => {
+                let x = try_opt!(
+                    try_opt!(resp.result.find("x"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find x field").as_f64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret x as float");
+
+                let y = try_opt!(
+                    try_opt!(resp.result.find("y"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find y field").as_f64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret y as float");
+
+                let width = try_opt!(
+                    try_opt!(resp.result.find("width"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find width field").as_f64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret width as float");
+
+                let height = try_opt!(
+                    try_opt!(resp.result.find("height"),
+                             ErrorStatus::UnknownError,
+                             "Failed to find height field").as_f64(),
+                    ErrorStatus::UnknownError,
+                    "Failed to interpret width as float");
+
+                WebDriverResponse::ElementRect(ElementRectResponse::new(x, y, width, height))
+            },
+            FullscreenWindow => {
                 let width = try_opt!(
                     try_opt!(resp.result.find("width"),
                              ErrorStatus::UnknownError,
@@ -765,7 +830,10 @@ impl MarionetteSession {
                     ErrorStatus::UnknownError,
                     "Failed to interpret y as integer");
 
-                WebDriverResponse::WindowRect(RectResponse::new(x, y, width, height))
+                WebDriverResponse::WindowRect(WindowRectResponse {x: x,
+                                                                  y: y,
+                                                                  width: width,
+                                                                  height: height})
             },
             GetCookies => {
                 let cookies = try!(self.process_cookies(&resp.result));