--- a/testing/geckodriver/CHANGES.md
+++ b/testing/geckodriver/CHANGES.md
@@ -1,13 +1,22 @@
 Change log
 ==========
 
 All notable changes to this program is documented in this file.
 
+
+Unreleased
+----------
+
+### Added
+
+- Support for the new chrome element identifier in Marionette.
+
+
 0.20.1 (2018-04-06)
 -------------------
 
 ### Fixed
 
 - Avoid attempting to kill Firefox process that has stopped.
 
   With the change to allow Firefox enough time to shut down in

--- a/testing/geckodriver/src/marionette.rs
+++ b/testing/geckodriver/src/marionette.rs
@@ -50,16 +50,18 @@ use webdriver::error::{ErrorStatus, WebD
 use webdriver::server::{WebDriverHandler, Session};
 use webdriver::httpapi::{WebDriverExtensionRoute};
 
 use capabilities::{FirefoxCapabilities, FirefoxOptions};
 use logging;
 use prefs;
 
 const DEFAULT_HOST: &'static str = "localhost";
+const CHROME_ELEMENT_KEY: &'static str = "chromeelement-9fc5-4b51-a3c8-01716eedeb04";
+const LEGACY_ELEMENT_KEY: &'static str = "ELEMENT";
 
 pub fn extension_routes() -> Vec<(Method, &'static str, GeckoExtensionRoute)> {
     return vec![(Method::Get, "/session/{sessionId}/moz/context", GeckoExtensionRoute::GetContext),
              (Method::Post, "/session/{sessionId}/moz/context", GeckoExtensionRoute::SetContext),
              (Method::Post,
               "/session/{sessionId}/moz/xbl/{elementId}/anonymous_children",
               GeckoExtensionRoute::XblAnonymousChildren),
              (Method::Post,
@@ -642,35 +644,36 @@ impl MarionetteSession {
                 self.session_id = session_id.to_string().clone();
             },
             _ => {}
         }
         Ok(())
     }
 
     fn to_web_element(&self, json_data: &Json) -> WebDriverResult<WebElement> {
-        let data = try_opt!(json_data.as_object(),
-                            ErrorStatus::UnknownError,
-                            "Failed to convert data to an object");
+        let data = try_opt!(
+            json_data.as_object(),
+            ErrorStatus::UnknownError,
+            "Failed to convert data to an object"
+        );
+
+        let web_element = data.get(ELEMENT_KEY);
+        let chrome_element = data.get(CHROME_ELEMENT_KEY);
+        let legacy_element = data.get(LEGACY_ELEMENT_KEY);
+
+        let value = try_opt!(
+            web_element.or(chrome_element).or(legacy_element),
+            ErrorStatus::UnknownError,
+            "Failed to extract web element from Marionette response"
+        );
         let id = try_opt!(
-            try_opt!(
-                match data.get("ELEMENT") {
-                    Some(id) => Some(id),
-                    None => {
-                        match data.get(ELEMENT_KEY) {
-                            Some(id) => Some(id),
-                            None => None
-                        }
-                    }
-                },
-                ErrorStatus::UnknownError,
-                "Failed to extract Web Element from response").as_string(),
+            value.as_string(),
             ErrorStatus::UnknownError,
-            "Failed to convert id value to string"
-            ).to_string();
+            "Failed to convert web element reference value to string"
+        ).to_string();
         Ok(WebElement::new(id))
     }
 
     pub fn next_command_id(&mut self) -> u64 {
         self.command_id = self.command_id + 1;
         self.command_id
     }