diff --git a/src/constants.ts b/src/constants.ts
new file mode 100644
index 0000000000..6a86e9e55d
--- /dev/null
+++ b/src/constants.ts
@@ -0,0 +1 @@
+export const resolved_promise = Promise.resolve();
diff --git a/src/runtime/internal/scheduler.ts b/src/runtime/internal/scheduler.ts
index 568739e4f8..9d9e6ec539 100644
--- a/src/runtime/internal/scheduler.ts
+++ b/src/runtime/internal/scheduler.ts
@@ -1,5 +1,6 @@
 import { run_all } from './utils';
 import { set_current_component } from './lifecycle';
+import { resolved_promise } from '../../constants';
 
 export const dirty_components = [];
 export const intros = { enabled: false };
@@ -8,7 +9,6 @@ export const binding_callbacks = [];
 const render_callbacks = [];
 const flush_callbacks = [];
 
-const resolved_promise = Promise.resolve();
 let update_scheduled = false;
 
 export function schedule_update() {
diff --git a/src/runtime/internal/transitions.ts b/src/runtime/internal/transitions.ts
index 21d67a12ba..ded0a657be 100644
--- a/src/runtime/internal/transitions.ts
+++ b/src/runtime/internal/transitions.ts
@@ -5,12 +5,13 @@ import { create_rule, delete_rule } from './style_manager';
 import { custom_event } from './dom';
 import { add_render_callback } from './scheduler';
 import { TransitionConfig } from '../transition';
+import { resolved_promise } from '../../constants';
 
 let promise: Promise<void>|null;
 
 function wait() {
 	if (!promise) {
-		promise = Promise.resolve();
+		promise = resolved_promise;
 		promise.then(() => {
 			promise = null;
 		});
diff --git a/src/runtime/motion/spring.ts b/src/runtime/motion/spring.ts
index 8d2056256c..5de2604706 100644
--- a/src/runtime/motion/spring.ts
+++ b/src/runtime/motion/spring.ts
@@ -1,6 +1,7 @@
 import { Readable, writable } from 'svelte/store';
 import { loop, now, Task } from 'svelte/internal';
 import { is_date } from './utils';
+import { resolved_promise } from '../../constants';
 
 interface TickContext<T> {
 	inv_mass: number;
@@ -89,7 +90,7 @@ export function spring<T=any>(value?: T, opts: SpringOpts = {}): Spring<T> {
 			last_time = now();
 			last_value = new_value;
 			store.set(value = target_value);
-			return Promise.resolve();
+			return resolved_promise;
 		} else if (opts.soft) {
 			const rate = opts.soft === true ? .5 : +opts.soft;
 			inv_mass_recovery_rate = 1 / (rate * 60);
diff --git a/src/runtime/motion/tweened.ts b/src/runtime/motion/tweened.ts
index 8fa5ebaba6..f40bc7e81b 100644
--- a/src/runtime/motion/tweened.ts
+++ b/src/runtime/motion/tweened.ts
@@ -2,6 +2,7 @@ import { Readable, writable } from 'svelte/store';
 import { assign, is_function, loop, now, Task } from 'svelte/internal';
 import { linear } from 'svelte/easing';
 import { is_date } from './utils';
+import { resolved_promise } from '../../constants';
 
 function get_interpolator(a, b) {
 	if (a === b || a !== a) return () => a;
@@ -78,7 +79,7 @@ export function tweened<T>(value?: T, defaults: Options<T> = {}): Tweened<T> {
 	function set(new_value: T, opts?: Options<T>) {
 		if (value == null) {
 			store.set(value = new_value);
-			return Promise.resolve();
+			return resolved_promise;
 		}
 
 		target_value = new_value;
@@ -100,7 +101,7 @@ export function tweened<T>(value?: T, defaults: Options<T> = {}): Tweened<T> {
 			}
 
 			store.set(value = target_value);
-			return Promise.resolve();
+			return resolved_promise;
 		}
 
 		const start = now() + delay;
diff --git a/src/runtime/tsconfig.json b/src/runtime/tsconfig.json
index f3b4691b41..a58a02f42b 100644
--- a/src/runtime/tsconfig.json
+++ b/src/runtime/tsconfig.json
@@ -1,6 +1,6 @@
 {
 	"extends": "../../tsconfig.json",
-	"include": ["."],
+	"include": [".", "../constants.ts"],
 
 	"compilerOptions": {
 		"lib": ["es2015", "dom", "dom.iterable"],