--- a/testing/marionette/element.js
+++ b/testing/marionette/element.js
@@ -667,17 +667,17 @@ ElementManager.prototype = {
  */
 function implicitlyWaitFor(func, timeout, interval = 100) {
   let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
 
   return new Promise((resolve, reject) => {
     let startTime = new Date().getTime();
     let endTime = startTime + timeout;
 
-    let observer = function() {
+    let onTimer = function() {
       let res;
       try {
         res = func();
       } catch (e) {
         reject(e);
       }
 
       // empty arrays evaluate to true in JS,
@@ -687,17 +687,21 @@ function implicitlyWaitFor(func, timeout
       // allowing |func| to be evaluated at least once
       let col = element.isElementCollection(res);
       if (((col && res.length > 0 ) || (!col && !!res)) ||
           (startTime == endTime || new Date().getTime() >= endTime)) {
         resolve(res);
       }
     };
 
-    timer.init(observer, interval, Ci.nsITimer.TYPE_REPEATING_SLACK);
+    // Run a check immediately so we do not cause a delay in execution
+    // due to the set timer interval.
+    onTimer();
+
+    timer.init(onTimer, interval, Ci.nsITimer.TYPE_REPEATING_SLACK);
 
   // cancel timer and return result for yielding
   }).then(res => {
     timer.cancel();
     return res;
   });
 }