diff --git a/README.md b/README.md
index 7b49452..734f66c 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ Exclude a specific Python version:
 ```yaml
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]