diff --git a/.github/workflows/unit_tests.yaml b/.github/workflows/unit_tests.yaml
index b6a3d589349..4b49333c814 100644
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -228,8 +228,8 @@ jobs:
           SPACK_TEST_SOLVER: original
       run: |
           whoami && echo $HOME && cd $HOME
-          git clone https://github.com/spack/spack.git && cd spack
-          git fetch origin ${{ github.ref }}:test-branch
+          git clone "${{ github.server_url }}/${{ github.repository }}.git" && cd spack
+          git fetch origin "${{ github.ref }}:test-branch"
           git checkout test-branch
           bin/spack unit-test -x
     - name: Run unit tests (only package tests)
@@ -240,8 +240,8 @@ jobs:
           SPACK_TEST_SOLVER: original
       run: |
           whoami && echo $HOME && cd $HOME
-          git clone https://github.com/spack/spack.git && cd spack
-          git fetch origin ${{ github.ref }}:test-branch
+          git clone "${{ github.server_url }}/${{ github.repository }}.git" && cd spack
+          git fetch origin "${{ github.ref }}:test-branch"
           git checkout test-branch
           bin/spack unit-test -x -m "not maybeslow" -k "package_sanity"