diff --git a/src/lib/es2018.promise.d.ts b/src/lib/es2018.promise.d.ts
index 070c4972f11..49171882e66 100644
--- a/src/lib/es2018.promise.d.ts
+++ b/src/lib/es2018.promise.d.ts
@@ -8,5 +8,5 @@ interface Promise<T> {
      * @param onfinally The callback to execute when the Promise is settled (fulfilled or rejected).
      * @returns A Promise for the completion of the callback.
      */
-    finally(onfinally?: (() => void) | undefined | null): Promise<T>;
+    finally(deferred onfinally?: (() => void) | undefined | null): Promise<T>;
 }
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 33bbb991474..0ed54745a74 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1516,7 +1516,7 @@ interface PromiseLike<T> {
      * @param onrejected The callback to execute when the Promise is rejected.
      * @returns A Promise for the completion of which ever callback is executed.
      */
-    then<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | null, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | null): PromiseLike<TResult1 | TResult2>;
+    then<TResult1 = T, TResult2 = never>(deferred onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | null, deferred onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | null): PromiseLike<TResult1 | TResult2>;
 }
 
 /**
@@ -1529,14 +1529,14 @@ interface Promise<T> {
      * @param onrejected The callback to execute when the Promise is rejected.
      * @returns A Promise for the completion of which ever callback is executed.
      */
-    then<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | null, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | null): Promise<TResult1 | TResult2>;
+    then<TResult1 = T, TResult2 = never>(deferred onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | null, deferred onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | null): Promise<TResult1 | TResult2>;
 
     /**
      * Attaches a callback for only the rejection of the Promise.
      * @param onrejected The callback to execute when the Promise is rejected.
      * @returns A Promise for the completion of the callback.
      */
-    catch<TResult = never>(onrejected?: ((reason: any) => TResult | PromiseLike<TResult>) | undefined | null): Promise<T | TResult>;
+    catch<TResult = never>(deferred onrejected?: ((reason: any) => TResult | PromiseLike<TResult>) | undefined | null): Promise<T | TResult>;
 }
 
 /**