diff --git a/.github/workflows/unit_tests.yaml b/.github/workflows/unit_tests.yaml
index e45e1aad1b..804d7fa125 100644
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -283,8 +283,6 @@ jobs:
           useradd spack-test
           chown -R spack-test .
     - name: Run unit tests
-      env:
-          SPACK_PYTHON: /usr/libexec/platform-python
       shell: runuser -u spack-test -- bash {0}
       run: |
           source share/spack/setup-env.sh
diff --git a/bin/spack b/bin/spack
index 14fd037c1e..a4c442227d 100755
--- a/bin/spack
+++ b/bin/spack
@@ -11,7 +11,8 @@
 # See https://stackoverflow.com/a/47886254
 """:"
 # prefer SPACK_PYTHON environment variable, python3, python, then python2
-for cmd in "${SPACK_PYTHON:-}" python3 python python2; do
+SPACK_PREFERRED_PYTHONS="python3 python python2 /usr/libexec/platform-python"
+for cmd in "${SPACK_PYTHON:-}" ${SPACK_PREFERRED_PYTHONS}; do
     if command -v > /dev/null "$cmd"; then
         export SPACK_PYTHON="$(command -v "$cmd")"
         exec "${SPACK_PYTHON}" "$0" "$@"