diff --git a/.github/actions/test_gem/action.yml b/.github/actions/test_gem/action.yml
index 974d15388..7b429a72a 100644
--- a/.github/actions/test_gem/action.yml
+++ b/.github/actions/test_gem/action.yml
@@ -82,6 +82,13 @@ runs:
         ruby-version: "${{ inputs.ruby }}"
         bundler:  "latest"
         working-directory: "${{ steps.setup.outputs.gem_dir }}"
+    # Perms workaround. See https://github.com/actions/runner-images/issues/10215
+    - name: Fix GEM_HOME permissions on GitHub Actions Runner
+      if: "${{ steps.setup.outputs.appraisals == 'true' }}"
+      shell: bash
+      run: |
+        # 🛠️😭 Fix GEM_HOME permissions 😭🛠️
+        chmod -R o-w $(gem env home)
     - name: Install dependencies and generate appraisals
       if: "${{ steps.setup.outputs.appraisals == 'true' }}"
       shell: bash