diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 457ddb3bab..9a50cae9ba 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,10 @@ jobs:
     - uses: actions/setup-node@v1
     - run: 'npm i && npm run lint'
   Unit:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-node@v1
diff --git a/site/content/docs/03-run-time.md b/site/content/docs/03-run-time.md
index 97eabd1146..460c393e7e 100644
--- a/site/content/docs/03-run-time.md
+++ b/site/content/docs/03-run-time.md
@@ -287,7 +287,9 @@ The second argument to `readable` is the same as the second argument to `writabl
 ```js
 import { readable } from 'svelte/store';
 
-const time = readable(new Date(), set => {
+const time = readable(null, set => {
+	set(new Date());
+
 	const interval = setInterval(() => {
 		set(new Date());
 	}, 1000);