diff --git a/backend/tests/test_docker.py b/backend/tests/test_docker.py
index 48b040b..29221be 100644
--- a/backend/tests/test_docker.py
+++ b/backend/tests/test_docker.py
@@ -117,8 +117,15 @@ def test_compose_declares_required_services():
 def test_compose_declares_required_secrets_and_volumes():
     compose = yaml.safe_load(COMPOSE_FILE.read_text())
     secrets = compose.get("secrets", {})
-    for required in ("cyclone_db_key", "cyclone_admin_password"):
+    for required in ("cyclone_db_key", "cyclone_admin_password", "cyclone_sftp_password"):
         assert required in secrets, f"compose must declare secret {required!r}"
+    # SP26: the SFTP secret must point at the same /etc/cyclone/secrets/ tree
+    # the host operator manages. Catch typos in the file path here so a
+    # rename breaks the test, not a production deploy.
+    assert (
+        secrets["cyclone_sftp_password"]["file"]
+        == "/etc/cyclone/secrets/sftp_password"
+    )
     volumes = compose.get("volumes", {})
     for required in (
         "cyclone_db",
@@ -142,6 +149,22 @@ def test_compose_backend_wires_backup_autostart():
     assert "CYCLONE_BACKUP_RETENTION_DAYS" in env
 
 
+def test_compose_backend_wires_sftp_password_file_env_var():
+    """SP26 — the backend must wire CYCLONE_SFTP_PASSWORD_FILE to the
+    mounted Docker secret so the MFT password resolves from
+    /run/secrets/cyclone_sftp_password without an env-var export."""
+    compose = yaml.safe_load(COMPOSE_FILE.read_text())
+    backend = compose["services"]["backend"]
+    env = backend.get("environment", {})
+    assert env.get("CYCLONE_SFTP_PASSWORD_FILE") == "/run/secrets/cyclone_sftp_password", (
+        "backend must wire CYCLONE_SFTP_PASSWORD_FILE to the Docker secret mount"
+    )
+    backend_secrets = backend.get("secrets", [])
+    assert any(
+        _volume_source(s) == "cyclone_sftp_password" for s in backend_secrets
+    ), "backend must reference the cyclone_sftp_password Docker secret"
+
+
 @pytest.mark.skipif(
     not _has_docker(), reason="docker not on PATH; skipping Dockerfile parse check"
 )