diff --git a/lib/extend.js b/lib/extend.js
index eea88da..1203780 100644
--- a/lib/extend.js
+++ b/lib/extend.js
@@ -6,6 +6,21 @@ module.exports = function (Potential, $Promise) {
 
   //----- promise methods -----
 
+  $Promise.debounce = function (sourceFn) {
+    var pending;
+    function resetPending () {
+     pending = null;
+    }
+    resetPending();
+    return function () {
+      if (!pending) {
+        pending = Promise.resolve(sourceFn.apply(this, arguments));
+        pending.then(resetPending, resetPending);
+      }
+      return pending;
+    };
+  };
+
   // syntactic sugar for adding error handlers
   $Promise.prototype.catch = function (onRejected) {
     return this.then(null, onRejected);