diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 491a702..ac9efaa 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -22,22 +22,22 @@ jobs:
         python: [ '3.8', '3.9', 'pypy-3.9', '3.10', '3.11', '3.12', '3.13' ]
         include:
           - os: macos-13
-            python: 3.8
+            python: '3.8'
           - os: macos-13
-            python: 3.9
+            python: '3.9'
           - os: macos-13
-            python: 3.10
+            python: '3.10'
           - os: macos-13
-            python: 3.11
+            python: '3.11'
         exclude:
           - os: macos-latest  # Python 3.8 unavailable on macos-14
-            python: 3.8
+            python: '3.8'
           - os: macos-latest  # Python 3.9 unavailable on macos-14
-            python: 3.9
+            python: '3.9'
           - os: macos-latest  # "ImportError: dlopen(.../probe.cpython-311-darwin.so, 0x002): bad bind opcode 0x00"
-            python: 3.10
+            python: '3.10'
           - os: macos-latest  # "ImportError: dlopen(.../probe.cpython-311-darwin.so, 0x002): bad bind opcode 0x00"
-            python: 3.11
+            python: '3.11'
 
     steps:
     - uses: actions/checkout@v3