diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 36b0dfe08..eed5220fa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
         skippable: [false]
         include:
-          - os: macos-latest
+          - os: 'macos-latest'
             skippable: true
           - java-version: 9
             skippable: true