diff --git a/spec/test-utils.js b/spec/test-utils.js
index 16ec18898..022f84e8c 100644
--- a/spec/test-utils.js
+++ b/spec/test-utils.js
@@ -256,7 +256,7 @@ HttpResponse.prototype.request = function HttpResponse(
     if (!next) { // no more things to return
         if (method === "GET" && path === "/sync" && this.ignoreUnhandledSync) {
             logger.log("MatrixClient[UT] Ignoring.");
-            return Promise.defer().promise;
+            return new Promise(() => {});
         }
         if (this.pendingLookup) {
             if (this.pendingLookup.method === method
@@ -271,7 +271,7 @@ HttpResponse.prototype.request = function HttpResponse(
             );
         }
         this.pendingLookup = {
-            promise: Promise.defer().promise,
+            promise: new Promise(() => {}),
             method: method,
             path: path,
         };
@@ -308,10 +308,10 @@ HttpResponse.prototype.request = function HttpResponse(
     } else if (method === "GET" && path === "/sync" && this.ignoreUnhandledSync) {
         logger.log("MatrixClient[UT] Ignoring.");
         this.httpLookups.unshift(next);
-        return Promise.defer().promise;
+        return new Promise(() => {});
     }
     expect(true).toBe(false, "Expected different request. " + logLine);
-    return Promise.defer().promise;
+    return new Promise(() => {});
 };
 
 HttpResponse.KEEP_ALIVE_PATH = "/_matrix/client/versions";
diff --git a/spec/unit/matrix-client.spec.js b/spec/unit/matrix-client.spec.js
index 19f426609..bf752c3ca 100644
--- a/spec/unit/matrix-client.spec.js
+++ b/spec/unit/matrix-client.spec.js
@@ -83,7 +83,7 @@ describe("MatrixClient", function() {
                 );
             }
             pendingLookup = {
-                promise: Promise.defer().promise,
+                promise: new Promise(() => {}),
                 method: method,
                 path: path,
             };
@@ -119,7 +119,7 @@ describe("MatrixClient", function() {
             return Promise.resolve(next.data);
         }
         expect(true).toBe(false, "Expected different request. " + logLine);
-        return Promise.defer().promise;
+        return new Promise(() => {});
     }
 
     beforeEach(function() {
@@ -171,7 +171,7 @@ describe("MatrixClient", function() {
         // a DIFFERENT test (pollution between tests!) - we return unresolved
         // promises to stop the client from continuing to run.
         client._http.authedRequest.mockImplementation(function() {
-            return Promise.defer().promise;
+            return new Promise(() => {});
         });
     });