diff --git a/dom/inputmethod/forms.js b/dom/inputmethod/forms.js
index 7a3e04fbfac..b43d4d7573c 100644
--- a/dom/inputmethod/forms.js
+++ b/dom/inputmethod/forms.js
@@ -224,7 +224,8 @@ let FormAssistant = {
   scrollIntoViewTimeout: null,
   _focusedElement: null,
   _focusCounter: 0, // up one for every time we focus a new element
-  _observer: null,
+  _focusDeleteObserver: null,
+  _focusContentObserver: null,
   _documentEncoder: null,
   _editor: null,
   _editing: false,
@@ -250,9 +251,13 @@ let FormAssistant = {
 
     if (this.focusedElement) {
       this.focusedElement.removeEventListener('compositionend', this);
-      if (this._observer) {
-        this._observer.disconnect();
-        this._observer = null;
+      if (this._focusDeleteObserver) {
+        this._focusDeleteObserver.disconnect();
+        this._focusDeleteObserver = null;
+      }
+      if (this._focusContentObserver) {
+        this._focusContentObserver.disconnect();
+        this._focusContentObserver = null;
       }
       if (this._selectionPrivate) {
         this._selectionPrivate.removeSelectionListener(this);
@@ -292,7 +297,7 @@ let FormAssistant = {
 
       // If our focusedElement is removed from DOM we want to handle it properly
       let MutationObserver = element.ownerDocument.defaultView.MutationObserver;
-      this._observer = new MutationObserver(function(mutations) {
+      this._focusDeleteObserver = new MutationObserver(function(mutations) {
         var del = [].some.call(mutations, function(m) {
           return [].some.call(m.removedNodes, function(n) {
             return n.contains(element);
@@ -305,10 +310,23 @@ let FormAssistant = {
         }
       });
 
-      this._observer.observe(element.ownerDocument.body, {
+      this._focusDeleteObserver.observe(element.ownerDocument.body, {
         childList: true,
         subtree: true
       });
+
+      // If contenteditable, also add a mutation observer on its content and
+      // call selectionChanged when a change occurs
+      if (isContentEditable(element)) {
+        this._focusContentObserver = new MutationObserver(function() {
+          this.updateSelection();
+        }.bind(this));
+
+        this._focusContentObserver.observe(element, {
+          childList: true,
+          subtree: true
+        });
+      }
     }
 
     this.focusedElement = element;
diff --git a/dom/inputmethod/mochitest/file_test_contenteditable.html b/dom/inputmethod/mochitest/file_test_contenteditable.html
new file mode 100644
index 00000000000..c7492e51356
--- /dev/null
+++ b/dom/inputmethod/mochitest/file_test_contenteditable.html
@@ -0,0 +1,17 @@
+<!DOCTYPE HTML>
+<html>
+<body>
+<div id="text" contenteditable>Jan Jongboom</div>
+<script type="application/javascript;version=1.7">
+  var t = document.querySelector('#text');
+
+  t.focus();
+  var range = document.createRange();
+  range.selectNodeContents(t);
+  range.collapse(false);
+  var selection = window.getSelection();
+  selection.removeAllRanges();
+  selection.addRange(range);
+</script>
+</body>
+</html>
diff --git a/dom/inputmethod/mochitest/mochitest.ini b/dom/inputmethod/mochitest/mochitest.ini
index f20d3851528..7f5b936723b 100644
--- a/dom/inputmethod/mochitest/mochitest.ini
+++ b/dom/inputmethod/mochitest/mochitest.ini
@@ -6,6 +6,7 @@ support-files =
   file_inputmethod.html
   file_inputmethod_1043828.html
   file_test_app.html
+  file_test_contenteditable.html
   file_test_sendkey_cancel.html
   file_test_sms_app.html
   file_test_sms_app_1066515.html
@@ -18,6 +19,7 @@ support-files =
 [test_bug978918.html]
 [test_bug1026997.html]
 [test_bug1043828.html]
+[test_bug1059163.html]
 [test_bug1066515.html]
 [test_delete_focused_element.html]
 [test_sendkey_cancel.html]
diff --git a/dom/inputmethod/mochitest/test_bug1059163.html b/dom/inputmethod/mochitest/test_bug1059163.html
new file mode 100644
index 00000000000..77c0a575c54
--- /dev/null
+++ b/dom/inputmethod/mochitest/test_bug1059163.html
@@ -0,0 +1,77 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1059163
+-->
+<head>
+  <title>Basic test for repeat sendKey events</title>
+  <script type="application/javascript;version=1.7" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript;version=1.7" src="inputmethod_common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1059163">Mozilla Bug 1059163</a>
+<p id="display"></p>
+<pre id="test">
+<script class="testbody" type="application/javascript;version=1.7">
+inputmethod_setup(function() {
+  runTest();
+});
+
+// The frame script running in the file
+function appFrameScript() {
+  addMessageListener('test:InputMethod:clear', function() {
+    var t = content.document.getElementById('text');
+    t.innerHTML = '';
+  });
+}
+
+function runTest() {
+  let im = navigator.mozInputMethod;
+
+  // Set current page as an input method.
+  SpecialPowers.wrap(im).setActive(true);
+
+  // Create an app frame to recieve keyboard inputs.
+  let app = document.createElement('iframe');
+  app.src = 'file_test_contenteditable.html';
+  app.setAttribute('mozbrowser', true);
+  document.body.appendChild(app);
+  app.addEventListener('mozbrowserloadend', function() {
+    let mm = SpecialPowers.getBrowserFrameMessageManager(app);
+
+    function register() {
+      im.inputcontext.onselectionchange = function() {
+        im.inputcontext.onselectionchange = null;
+
+        is(im.inputcontext.textBeforeCursor, '', 'textBeforeCursor');
+        is(im.inputcontext.textBeforeCursor, '', 'textAfterCursor');
+        is(im.inputcontext.selectionStart, 0, 'selectionStart');
+        is(im.inputcontext.selectionEnd, 0, 'selectionEnd');
+
+        inputmethod_cleanup();
+      };
+
+      mm.sendAsyncMessage('test:InputMethod:clear');
+    }
+
+    if (im.inputcontext) {
+       register();
+    }
+    else {
+      im.oninputcontextchange = function() {
+        if (im.inputcontext) {
+          im.oninputcontextchange = null;
+          register();
+        }
+      };
+    }
+
+    mm.loadFrameScript('data:,(' + appFrameScript.toString() + ')();', false);
+  });
+}
+</script>
+</pre>
+</body>
+</html>
+
