diff --git a/browser/devtools/styleeditor/StyleEditor.jsm b/browser/devtools/styleeditor/StyleEditor.jsm
index 092e2bd8983..06cf249ae9d 100644
--- a/browser/devtools/styleeditor/StyleEditor.jsm
+++ b/browser/devtools/styleeditor/StyleEditor.jsm
@@ -229,6 +229,8 @@ StyleEditor.prototype = {
     };
 
     sourceEditor.init(aElement, config, function onSourceEditorReady() {
+      setupBracketCompletion(sourceEditor);
+
       sourceEditor.addEventListener(SourceEditor.EVENTS.TEXT_CHANGED,
                                     function onTextChanged(aEvent) {
         this.updateStyleSheet();
@@ -1132,3 +1134,48 @@ function repeat(aText, aCount)
 {
   return (new Array(aCount + 1)).join(aText);
 }
+
+/**
+ * Set up bracket completion on a given SourceEditor.
+ * This automatically closes the following CSS brackets: "{", "(", "["
+ *
+ * @param SourceEditor aSourceEditor
+ */
+function setupBracketCompletion(aSourceEditor)
+{
+  let editorElement = aSourceEditor.editorElement;
+  let pairs = {
+    123: { // {
+      closeString: "}",
+      closeKeyCode: Ci.nsIDOMKeyEvent.DOM_VK_CLOSE_BRACKET
+    },
+    40: { // (
+      closeString: ")",
+      closeKeyCode: Ci.nsIDOMKeyEvent.DOM_VK_0
+    },
+    91: { // [
+      closeString: "]",
+      closeKeyCode: Ci.nsIDOMKeyEvent.DOM_VK_CLOSE_BRACKET
+    },
+  };
+
+  editorElement.addEventListener("keypress", function onKeyPress(aEvent) {
+    let pair = pairs[aEvent.charCode];
+    if (!pair) {
+      return true;
+    }
+
+    // We detected an open bracket, sending closing character
+    let keyCode = pair.closeKeyCode;
+    let charCode = pair.closeString.charCodeAt(0);
+    let modifiers = 0;
+    let utils = editorElement.ownerDocument.defaultView.
+                  QueryInterface(Ci.nsIInterfaceRequestor).
+                  getInterface(Ci.nsIDOMWindowUtils);
+    let handled = utils.sendKeyEvent("keydown", keyCode, 0, modifiers);
+    utils.sendKeyEvent("keypress", 0, charCode, modifiers, !handled);
+    utils.sendKeyEvent("keyup", keyCode, 0, modifiers);
+    // and rewind caret
+    aSourceEditor.setCaretOffset(aSourceEditor.getCaretOffset() - 1);
+  }, false);
+}
diff --git a/browser/devtools/styleeditor/test/browser_styleeditor_new.js b/browser/devtools/styleeditor/test/browser_styleeditor_new.js
index c40215d0bdb..fea602970b6 100644
--- a/browser/devtools/styleeditor/test/browser_styleeditor_new.js
+++ b/browser/devtools/styleeditor/test/browser_styleeditor_new.js
@@ -5,7 +5,7 @@
 const TESTCASE_URI = TEST_BASE + "simple.html";
 
 const TRANSITION_CLASS = "moz-styleeditor-transitioning";
-
+const TESTCASE_CSS_SOURCE = "body{background-color:red;";
 
 function test()
 {
@@ -79,9 +79,13 @@ function testEditorAdded(aChrome, aEditor)
         is(computedStyle.backgroundColor, "rgb(255, 255, 255)",
            "content's background color is initially white");
 
-        for each (let c in "body{background-color:red;}") {
+        for each (let c in TESTCASE_CSS_SOURCE) {
           EventUtils.synthesizeKey(c, {}, gChromeWindow);
         }
+
+        is(aEditor.sourceEditor.getText(), TESTCASE_CSS_SOURCE + "}",
+           "rule bracket has been auto-closed");
+
       }, gChromeWindow) ;
     },