diff --git a/README.md b/README.md
index 5cd5472dd5e..6a120370f76 100644
--- a/README.md
+++ b/README.md
@@ -172,6 +172,14 @@ var q = ds.createQuery('Company')
     .filter('size <', 400);
 ~~~~
 
+To filter by key, use `__key__` for the property name. Filtering on keys
+stored as properties is not currently supported.
+
+~~~~ js
+var q = ds.createQuery('Company')
+    .filter('__key__ =', ['Company', 'Google'])
+~~~~
+
 In order to filter by ancestors, use `hasAncestor` helper.
 
 ~~~ js
diff --git a/regression/datastore.js b/regression/datastore.js
index eb7c50ea656..8db08131ee6 100644
--- a/regression/datastore.js
+++ b/regression/datastore.js
@@ -254,6 +254,16 @@ describe('datastore', function() {
       });
     });
 
+    it('should filter by key', function(done) {
+      var q = ds.createQuery('Character')
+          .filter('__key__ =', ['Character', 'Rickard']);
+      ds.runQuery(q, function(err, keys, objs, nextQuery) {
+        if (err) return done(err);
+        assert.equal(objs.length, 1);
+        done();
+      });
+    });
+
     it('should order queries', function(done) {
       var q = ds.createQuery('Character').order('+appearances');
       ds.runQuery(q, function(err, keys, objs, nextQuery) {