diff --git a/src/internal/animations.js b/src/internal/animations.js
index 355c0254e7..031bacc920 100644
--- a/src/internal/animations.js
+++ b/src/internal/animations.js
@@ -1,4 +1,5 @@
 import { transitionManager, linear, generateRule, hash } from './transitions.js';
+import { loop } from './loop.js';
 
 export function wrapAnimation(node, from, fn, params) {
 	if (!from) return;
@@ -68,7 +69,35 @@ export function wrapAnimation(node, from, fn, params) {
 		}
 	};
 
-	transitionManager.add(animation);
+	// transitionManager.add(animation);
+
+	transitionManager.active += 1;
+
+	const { abort, promise } = loop(() => {
+		const now = window.performance.now();
+
+		if (animation.program && now >= animation.program.end) {
+			animation.done();
+		}
+
+		if (animation.pending && now >= animation.pending.start) {
+			animation.start(animation.pending);
+		}
+
+		if (animation.running) {
+			animation.update(now);
+			return true;
+		}
+	});
+
+	promise.then(() => {
+		transitionManager.active -= 1;
+		if (!transitionManager.active) {
+			let i = transitionManager.stylesheet.cssRules.length;
+			while (i--) transitionManager.stylesheet.deleteRule(i);
+			transitionManager.activeRules = {};
+		}
+	});
 
 	if (info.tick) info.tick(0, 1);
 
diff --git a/src/internal/index.js b/src/internal/index.js
index 6b134b677d..f3654f6b77 100644
--- a/src/internal/index.js
+++ b/src/internal/index.js
@@ -3,6 +3,7 @@ export * from './await-block.js';
 export * from './dom.js';
 export * from './keyed-each.js';
 export * from './lifecycle.js';
+export * from './loop.js';
 export * from './scheduler.js';
 export * from './spread.js';
 export * from './ssr.js';
diff --git a/src/internal/loop.js b/src/internal/loop.js
new file mode 100644
index 0000000000..602a910cba
--- /dev/null
+++ b/src/internal/loop.js
@@ -0,0 +1,38 @@
+const tasks = new Set();
+let running = false;
+
+function run_tasks() {
+	tasks.forEach(task => {
+		if (!task[0]()) {
+			tasks.delete(task);
+			task[1]();
+		}
+	});
+
+	running = tasks.size > 0;
+	if (running) requestAnimationFrame(run_tasks);
+}
+
+export function clear_loops() {
+	// for testing...
+	tasks.forEach(task => tasks.delete(task));
+	running = false;
+}
+
+export function loop(fn) {
+	let task;
+
+	if (!running) {
+		running = true;
+		requestAnimationFrame(run_tasks);
+	}
+
+	return {
+		promise: new Promise(fulfil => {
+			tasks.add(task = [fn, fulfil]);
+		}),
+		abort() {
+			tasks.delete(task);
+		}
+	};
+}
\ No newline at end of file
diff --git a/src/internal/transitions.js b/src/internal/transitions.js
index 98418556a0..f90fa3d590 100644
--- a/src/internal/transitions.js
+++ b/src/internal/transitions.js
@@ -1,5 +1,6 @@
 import { createElement } from './dom.js';
 import { noop, run } from './utils.js';
+import { loop } from './loop.js';
 
 export function linear(t) {
 	return t;
@@ -83,8 +84,35 @@ export function wrapTransition(component, node, fn, params, intro) {
 			}
 
 			if (!this.running) {
+				transitionManager.active += 1;
+
 				this.running = true;
-				transitionManager.add(this);
+				// transitionManager.add(this);
+				const { abort, promise } = loop(() => {
+					const now = window.performance.now();
+
+					if (this.program && now >= this.program.end) {
+						this.done();
+					}
+
+					if (this.pending && now >= this.pending.start) {
+						this.start(this.pending);
+					}
+
+					if (this.running) {
+						this.update(now);
+						return true;
+					}
+				});
+
+				promise.then(() => {
+					transitionManager.active -= 1;
+					if (!transitionManager.active) {
+						let i = transitionManager.stylesheet.cssRules.length;
+						while (i--) transitionManager.stylesheet.deleteRule(i);
+						transitionManager.activeRules = {};
+					}
+				});
 			}
 		},
 
@@ -173,6 +201,7 @@ export function groupOutros() {
 }
 
 export var transitionManager = {
+	active: 0,
 	running: false,
 	transitions: [],
 	bound: null,
@@ -180,15 +209,6 @@ export var transitionManager = {
 	activeRules: {},
 	promise: null,
 
-	add(transition) {
-		this.transitions.push(transition);
-
-		if (!this.running) {
-			this.running = true;
-			requestAnimationFrame(this.bound || (this.bound = this.next.bind(this)));
-		}
-	},
-
 	addRule(rule, name) {
 		if (!this.stylesheet) {
 			const style = createElement('style');
@@ -202,40 +222,6 @@ export var transitionManager = {
 		}
 	},
 
-	next() {
-		this.running = false;
-
-		const now = window.performance.now();
-		let i = this.transitions.length;
-
-		while (i--) {
-			const transition = this.transitions[i];
-
-			if (transition.program && now >= transition.program.end) {
-				transition.done();
-			}
-
-			if (transition.pending && now >= transition.pending.start) {
-				transition.start(transition.pending);
-			}
-
-			if (transition.running) {
-				transition.update(now);
-				this.running = true;
-			} else if (!transition.pending) {
-				this.transitions.splice(i, 1);
-			}
-		}
-
-		if (this.running) {
-			requestAnimationFrame(this.bound);
-		} else if (this.stylesheet) {
-			let i = this.stylesheet.cssRules.length;
-			while (i--) this.stylesheet.deleteRule(i);
-			this.activeRules = {};
-		}
-	},
-
 	deleteRule(node, name) {
 		node.style.animation = node.style.animation
 			.split(', ')
diff --git a/src/motion/spring.js b/src/motion/spring.js
index ebac993f06..7d68377bd0 100644
--- a/src/motion/spring.js
+++ b/src/motion/spring.js
@@ -1,5 +1,6 @@
 import { writable } from 'svelte/store';
-import { add_task, is_date } from './utils.js';
+import { loop } from 'svelte/internal';
+import { is_date } from './utils.js';
 
 function get_initial_velocity(value) {
 	if (typeof value === 'number' || is_date(value)) return 0;
@@ -116,7 +117,7 @@ export function spring(value, opts = {}) {
 			last_time = window.performance.now();
 			settled = false;
 
-			task = add_task(() => {
+			task = loop(() => {
 				const time = window.performance.now();
 
 				({ value, settled } = tick_spring(
diff --git a/src/motion/tweened.js b/src/motion/tweened.js
index 020378408c..21ff8f70c7 100644
--- a/src/motion/tweened.js
+++ b/src/motion/tweened.js
@@ -1,7 +1,7 @@
 import { writable } from 'svelte/store';
-import { assign } from 'svelte/internal';
+import { assign, loop } from 'svelte/internal';
 import { linear } from 'svelte/easing';
-import { add_task, is_date } from './utils.js';
+import { is_date } from './utils.js';
 
 function get_interpolator(a, b) {
 	if (a === b || a !== a) return () => a;
@@ -76,7 +76,7 @@ export function tweened(value, defaults = {}) {
 		const start = window.performance.now() + delay;
 		let fn;
 
-		task = add_task(() => {
+		task = loop(() => {
 			const time = window.performance.now();
 			if (time < start) return true;
 
diff --git a/src/motion/utils.js b/src/motion/utils.js
index 986cec3ef4..97a764bf46 100644
--- a/src/motion/utils.js
+++ b/src/motion/utils.js
@@ -1,36 +1,3 @@
-const tasks = new Set();
-let running = false;
-
-function run_tasks() {
-	tasks.forEach(task => {
-		if (!task[0]()) {
-			tasks.delete(task);
-			task[1]();
-		}
-	});
-
-	running = tasks.size > 0;
-	if (running) requestAnimationFrame(run_tasks);
-}
-
-export function add_task(fn) {
-	let task;
-
-	if (!running) {
-		running = true;
-		requestAnimationFrame(run_tasks);
-	}
-
-	return {
-		promise: new Promise(fulfil => {
-			tasks.add(task = [fn, fulfil]);
-		}),
-		abort() {
-			tasks.delete(task);
-		}
-	};
-}
-
 export function is_date(obj) {
 	return Object.prototype.toString.call(obj) === '[object Date]';
 }
\ No newline at end of file
diff --git a/test/runtime/index.js b/test/runtime/index.js
index 88e2d0fe84..5569b444d1 100644
--- a/test/runtime/index.js
+++ b/test/runtime/index.js
@@ -3,7 +3,7 @@ import * as path from "path";
 import * as fs from "fs";
 import { rollup } from 'rollup';
 import * as virtual from 'rollup-plugin-virtual';
-import { transitionManager } from "../../internal.js";
+import { transitionManager, clear_loops } from "../../internal.js";
 
 import {
 	showOutput,
@@ -96,6 +96,7 @@ describe("runtime", () => {
 					// set of hacks to support transition tests
 					transitionManager.running = false;
 					transitionManager.transitions = [];
+					clear_loops();
 
 					const raf = {
 						time: 0,