diff --git a/.github/workflows/cross_platform_tests.yml b/.github/workflows/cross_platform_tests.yml
index 141c966..70398e3 100644
--- a/.github/workflows/cross_platform_tests.yml
+++ b/.github/workflows/cross_platform_tests.yml
@@ -23,7 +23,7 @@ jobs:
           # "windows-2022",
         ]
 
-    runs-on: matrix.os
+    runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4