diff --git a/docs/spec/domSpec.js b/docs/spec/domSpec.js
index d10db9dc7e82..cb4c00f250cb 100644
--- a/docs/spec/domSpec.js
+++ b/docs/spec/domSpec.js
@@ -9,11 +9,16 @@ describe('dom', function() {
   });
 
   describe('html', function() {
-    it('should add ids to all h tags', function() {
+    it('should add ids to h tags', function() {
       dom.html('<h1>Some Header</h1>');
       expect(dom.toString()).toContain('<h1 id="some-header">Some Header</h1>');
     });
 
+    it('should override existing h tag ids', function() {
+      dom.html('<h1 id="header">Some Header</h1>');
+      expect(dom.toString()).toContain('<h1 id="some-header">Some Header</h1>');
+    });
+
     it('should collect <a name> anchors too', function() {
       dom.html('<h2>Xxx <a name="foo"></a> and bar <a name="bar"></a>');
       expect(dom.anchors).toContain('foo');
diff --git a/docs/src/dom.js b/docs/src/dom.js
index e696faf4c1c7..cb15215df866 100644
--- a/docs/src/dom.js
+++ b/docs/src/dom.js
@@ -83,6 +83,7 @@ DOM.prototype = {
 
       var id = idFromCurrentHeaders(self.currentHeaders);
       self.anchors.push(id);
+      attrs = attrs.replace(/\sid=["'].+?["']/, '');
       return '<h' + level + attrs + ' id="' + id + '">' + content + '</h' + level + '>';
     });