--- a/toolkit/content/tests/chrome/findbar_window.xul
+++ b/toolkit/content/tests/chrome/findbar_window.xul
@@ -26,17 +26,17 @@
     ContentTask.setTestScope(window.opener.wrappedJSObject);
 
     var gPrefsvc = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefBranch);
 
     const SAMPLE_URL = "http://www.mozilla.org/";
     const SAMPLE_TEXT = "Some text in a text field.";
     const SEARCH_TEXT = "Text Test";
     const NOT_FOUND_TEXT = "This text is not on the page."
-    const ITERATOR_TIMEOUT = gPrefsvc.getIntPref("findbar.iteratorTimeout") + 20;
+    const ITERATOR_TIMEOUT = gPrefsvc.getIntPref("findbar.iteratorTimeout");
 
     var gFindBar = null;
     var gBrowser;
 
     var gClipboard = Cc["@mozilla.org/widget/clipboard;1"].getService(Ci.nsIClipboard);
     var gHasFindClipboard = gClipboard.supportsFindClipboard();
 
     var gStatusText;
@@ -250,17 +250,17 @@
         let listener = {
           onMatchesCountResult: function() {
             gFindBar.browser.finder.removeResultListener(listener);
             resolve();
           }
         };
         gFindBar.browser.finder.addResultListener(listener);
         // Make sure we resolve _at least_ after five times the find iterator timeout.
-        setTimeout(resolve, ITERATOR_TIMEOUT * 5);
+        setTimeout(resolve, (ITERATOR_TIMEOUT * 5) + 20);
       });
     }
 
     var enterStringIntoFindField = Task.async(function* (str, waitForResult = true) {
       for (let promise, i = 0; i < str.length; i++) {
         if (waitForResult) {
           promise = promiseFindResult();
         }
@@ -518,17 +518,17 @@
       ok(document.commandDispatcher.focusedElement == gFindBar._findField.inputField,
          "testFindCountUI: find field is not focused");
 
       let promise;
       let matchCase = gFindBar.getElement("find-case-sensitive");
       if (matchCase.checked) {
         promise = promiseFindResult();
         matchCase.click();
-        yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT));
+        yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT + 20));
         yield promise;
       }
 
       let foundMatches = gFindBar._foundMatches;
       let tests = [{
         text: "t",
         current: 5,
         total: 10,
@@ -553,26 +553,32 @@
         is(aMatches[2], String(aTest.total),
           `Total amount of matches should be ${aTest.total} for '${aTest.text}'`);
       }
 
       for (let test of tests) {
         gFindBar._findField.select();
         gFindBar._findField.focus();
 
-        yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT));
+        let timeout = ITERATOR_TIMEOUT;
+        if (test.text.length == 1)
+          timeout *= 4;
+        else if (test.text.length == 2)
+          timeout *= 2;
+        timeout += 20;
+        yield new Promise(resolve => setTimeout(resolve, timeout));
         yield enterStringIntoFindField(test.text, false);
         yield promiseMatchesCountResult();
         let matches = foundMatches.value.match(regex);
         if (!test.total) {
           ok(!matches, "No message should be shown when 0 matches are expected");
         } else {
           assertMatches(test, matches);
           for (let i = 1; i < test.total; i++) {
-            yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT));
+            yield new Promise(resolve => setTimeout(resolve, timeout));
             gFindBar.onFindAgainCommand();
             yield promiseMatchesCountResult();
             // test.current + 1, test.current + 2, ..., test.total, 1, ..., test.current
             let current = (test.current + i - 1) % test.total + 1;
             assertMatches({
               text: test.text,
               current: current,
               total: test.total
@@ -654,17 +660,17 @@
 
     function* testToggleEntireWord() {
       yield openFindbar();
       let promise = promiseFindResult();
       yield enterStringIntoFindField("Tex", false);
       let result = yield promise;
       is(result.result, Ci.nsITypeAheadFind.FIND_FOUND, "Text should be found");
 
-      yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT));
+      yield new Promise(resolve => setTimeout(resolve, ITERATOR_TIMEOUT + 20));
       promise = promiseFindResult();
       let check = gFindBar.getElement("find-entire-word");
       check.click();
       result = yield promise;
       is(result.result, Ci.nsITypeAheadFind.FIND_NOTFOUND, "Text should NOT be found");
 
       check.click();
       gFindBar.close(true);

--- a/toolkit/modules/FinderIterator.jsm
+++ b/toolkit/modules/FinderIterator.jsm
@@ -165,16 +165,20 @@ this.FinderIterator = {
   stop(cachePrevious = false) {
     if (!this.running)
       return;
 
     if (this._timer) {
       clearTimeout(this._timer);
       this._timer = null;
     }
+    if (this._runningFindResolver) {
+      this._runningFindResolver();
+      this._runningFindResolver = null;
+    }
 
     if (cachePrevious) {
       this._previousRanges = [].concat(this.ranges);
       this._previousParams = Object.assign({}, this._currentParams);
     } else {
       this._previousRanges = [];
       this._previousParams = null;
     }
@@ -215,16 +219,20 @@ this.FinderIterator = {
    * previous result invalid.
    * If the iterator is running, it will be stopped as soon as possible.
    */
   reset() {
     if (this._timer) {
       clearTimeout(this._timer);
       this._timer = null;
     }
+    if (this._runningFindResolver) {
+      this._runningFindResolver();
+      this._runningFindResolver = null;
+    }
 
     this._catchingUp.clear();
     this._currentParams = this._previousParams = null;
     this._previousRanges = [];
     this.ranges = [];
     this.running = false;
 
     this._notifyListeners("reset");
@@ -416,18 +424,32 @@ this.FinderIterator = {
    *                               is not, this identifier is used to learn if
    *                               it's supposed to still continue after a pause.
    * @yield {nsIDOMRange}
    */
   _findAllRanges: Task.async(function* (finder, spawnId) {
     if (this._timeout) {
       if (this._timer)
         clearTimeout(this._timer);
-      yield new Promise(resolve => this._timer = setTimeout(resolve, this._timeout));
-      this._timer = null;
+      if (this._runningFindResolver)
+        this._runningFindResolver();
+
+      let timeout = this._timeout;
+      let searchTerm = this._currentParams.word;
+      // Wait a little longer when the first or second character is typed into
+      // the findbar.
+      if (searchTerm.length == 1)
+        timeout *= 4;
+      else if (searchTerm.length == 2)
+        timeout *= 2;
+      yield new Promise(resolve => {
+        this._runningFindResolver = resolve;
+        this._timer = setTimeout(resolve, timeout);
+      });
+      this._timer = this._runningFindResolver = null;
       // During the timeout, we could have gotten the signal to stop iterating.
       // Make sure we do here.
       if (!this.running || spawnId !== this._spawnId)
         return;
     }
 
     this._notifyListeners("start", this.params);
 

--- a/toolkit/modules/tests/browser/browser_FinderHighlighter.js
+++ b/toolkit/modules/tests/browser/browser_FinderHighlighter.js
@@ -216,17 +216,22 @@ add_task(function* testModalResults() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   yield BrowserTestUtils.withNewTab(url, function* (browser) {
     let findbar = gBrowser.getFindBar();
 
     for (let [word, expectedResult] of tests) {
       yield promiseOpenFindbar(findbar);
       Assert.ok(!findbar.hidden, "Findbar should be open now.");
 
-      yield new Promise(resolve => setTimeout(resolve, kIteratorTimeout));
+      let timeout = kIteratorTimeout;
+      if (word.length == 1)
+        timeout *= 4;
+      else if (word.length == 2)
+        timeout *= 2;
+      yield new Promise(resolve => setTimeout(resolve, timeout));
       let promise = promiseTestHighlighterOutput(browser, word, expectedResult,
         expectedResult.extraTest);
       yield promiseEnterStringIntoFindField(findbar, word);
       yield promise;
 
       findbar.close(true);
     }
   });