diff --git a/.github/workflows/eval-manager-selftest.yml b/.github/workflows/eval-manager-selftest.yml
index 7a08052..d819949 100644
--- a/.github/workflows/eval-manager-selftest.yml
+++ b/.github/workflows/eval-manager-selftest.yml
@@ -28,6 +28,8 @@ jobs:
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.11"
+      - name: Compile Eval Manager sources
+        run: python -m compileall -q eval-manager
       - name: Run Eval Manager contract tests
         run: |
           python eval-manager/test_eval_manager.py
diff --git a/eval-manager/eval_manager.py b/eval-manager/eval_manager.py
index c922bd6..cf2895d 100644
--- a/eval-manager/eval_manager.py
+++ b/eval-manager/eval_manager.py
@@ -151,7 +151,7 @@ def _verify_freeze(contract: dict[str, Any], repo_root: Path) -> list[dict[str,
             raise ContractError(
                 "freeze.source_ref must be refs/tags/... or refs/heads/freeze/..."
             )
-    if expected_source_sha is None && expected_source_ref is None:
+    if expected_source_sha is None and expected_source_ref is None:
         raise ContractError("frozen phase requires freeze.source_sha or freeze.source_ref")
     identities = freeze.get("identities")
     if not isinstance(identities, list) or not identities: