diff --git a/lib/utils.js b/lib/utils.js
index 89199d2e..75ca6f8b 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -77,6 +77,13 @@ exports.merge = function (target, source, options) {
     }, mergeTarget);
 };
 
+exports.assign = function assignSingleSource(target, source) {
+    return Object.keys(source).reduce(function (acc, key) {
+        acc[key] = source[key];
+        return acc;
+    }, target);
+};
+
 exports.decode = function (str) {
     try {
         return decodeURIComponent(str.replace(/\+/g, ' '));
diff --git a/test/utils.js b/test/utils.js
index 0721dd8e..eff4011a 100644
--- a/test/utils.js
+++ b/test/utils.js
@@ -20,3 +20,15 @@ test('merge()', function (t) {
 
     t.end();
 });
+
+test('assign()', function (t) {
+    var target = { a: 1, b: 2 };
+    var source = { b: 3, c: 4 };
+    var result = utils.assign(target, source);
+
+    t.equal(result, target, 'returns the target');
+    t.deepEqual(target, { a: 1, b: 3, c: 4 }, 'target and source are merged');
+    t.deepEqual(source, { b: 3, c: 4 }, 'source is untouched');
+
+    t.end();
+});