diff --git a/testing/marionette/driver.js b/testing/marionette/driver.js
index 7eaef2af9a0a..45550ff67b69 100644
--- a/testing/marionette/driver.js
+++ b/testing/marionette/driver.js
@@ -2119,8 +2119,7 @@ GeckoDriver.prototype.getElementValueOfCssProperty = function(cmd, resp) {
       break;
 
     case Context.CONTENT:
-      resp.value = yield this.listener.getElementValueOfCssProperty(
-          {id: id, propertyName: prop});
+      resp.value = yield this.listener.getElementValueOfCssProperty(id, prop);
       break;
   }
 };
diff --git a/testing/marionette/listener.js b/testing/marionette/listener.js
index 5e4176a6bf1f..10a87239480c 100644
--- a/testing/marionette/listener.js
+++ b/testing/marionette/listener.js
@@ -211,6 +211,7 @@ let isElementSelectedFn = dispatch(isElementSelected);
 let getElementLocationFn = dispatch(getElementLocation);
 let clearElementFn = dispatch(clearElement);
 let isElementDisplayedFn = dispatch(isElementDisplayed);
+let getElementValueOfCssPropertyFn = dispatch(getElementValueOfCssProperty);
 
 /**
  * Start all message listeners
@@ -241,7 +242,7 @@ function startListeners() {
   addMessageListenerId("Marionette:getElementText", getElementTextFn);
   addMessageListenerId("Marionette:getElementTagName", getElementTagNameFn);
   addMessageListenerId("Marionette:isElementDisplayed", isElementDisplayedFn);
-  addMessageListenerId("Marionette:getElementValueOfCssProperty", getElementValueOfCssProperty);
+  addMessageListenerId("Marionette:getElementValueOfCssProperty", getElementValueOfCssPropertyFn);
   addMessageListenerId("Marionette:getElementSize", getElementSizeFn);  // deprecated
   addMessageListenerId("Marionette:getElementRect", getElementRectFn);
   addMessageListenerId("Marionette:isElementEnabled", isElementEnabledFn);
@@ -346,7 +347,7 @@ function deleteSession(msg) {
   removeMessageListenerId("Marionette:getElementText", getElementTextFn);
   removeMessageListenerId("Marionette:getElementTagName", getElementTagNameFn);
   removeMessageListenerId("Marionette:isElementDisplayed", isElementDisplayedFn);
-  removeMessageListenerId("Marionette:getElementValueOfCssProperty", getElementValueOfCssProperty);
+  removeMessageListenerId("Marionette:getElementValueOfCssProperty", getElementValueOfCssPropertyFn);
   removeMessageListenerId("Marionette:getElementSize", getElementSizeFn); // deprecated
   removeMessageListenerId("Marionette:getElementRect", getElementRectFn);
   removeMessageListenerId("Marionette:isElementEnabled", isElementEnabledFn);
@@ -1519,23 +1520,21 @@ function isElementDisplayed(id) {
 }
 
 /**
- * Return the property of the computed style of an element
+ * Retrieves the computed value of the given CSS property of the given
+ * web element.
  *
- * @param object aRequest
- *               'element' member holds the reference id to
- *               the element that will be checked
- *               'propertyName' is the CSS rule that is being requested
+ * @param {String} id
+ *     Web element reference.
+ * @param {String} prop
+ *     The CSS property to get.
+ *
+ * @return {String}
+ *     Effective value of the requested CSS property.
  */
-function getElementValueOfCssProperty(msg) {
-  let command_id = msg.json.command_id;
-  let propertyName = msg.json.propertyName;
-  try {
-    let el = elementManager.getKnownElement(msg.json.id, curFrame);
-    sendResponse({value: curFrame.document.defaultView.getComputedStyle(el, null).getPropertyValue(propertyName)},
-                 command_id);
-  } catch (e) {
-    sendError(e, command_id);
-  }
+function getElementValueOfCssProperty(id, prop) {
+  let el = elementManager.getKnownElement(id, curFrame);
+  let st = curFrame.document.defaultView.getComputedStyle(el, null);
+  return st.getPropertyValue(prop);
 }
 
 /**