diff --git a/pytest_abra/env_manager.py b/pytest_abra/env_manager.py
index ab3754a..8664624 100644
--- a/pytest_abra/env_manager.py
+++ b/pytest_abra/env_manager.py
@@ -44,6 +44,7 @@ class EnvManager:
     def _get_dependency_rules(env_files: list[EnvFile], RUNNER_DICT: dict[str, type["Runner"]]) -> list[DependencyRule]:
         dependency_rules: list[DependencyRule] = []
         for env_file in env_files:
+            assert env_file.env_type in RUNNER_DICT, f"no runner for env_type={env_file.env_type} found in RUNNER_DICT"
             child_runner_class = RUNNER_DICT[env_file.env_type]
             for dependency in child_runner_class.dependencies:
                 dependency_rule = DependencyRule(child=child_runner_class.env_type, dependency=dependency)
diff --git a/tests/test_env_resolution.py b/tests/test_env_resolution.py
index ddb5fc4..bbdf8f0 100644
--- a/tests/test_env_resolution.py
+++ b/tests/test_env_resolution.py
@@ -102,3 +102,17 @@ def test_env_manager() -> None:
     assert ENV.env_files[0].env_type == "authentik"
     assert ENV.env_files[1].env_type == "authentik"
     assert ENV.env_files[2].env_type == "wordpress"
+
+
+def test_RUNNER_DICT_missing_key() -> None:
+    """RUNNER_DICT missing wordpress key while .env file with TYPE=wordpress given"""
+    env_paths_list = [
+        Path("envfiles/blog.test.dev.local-it.cloud.env"),  # wordpress
+        Path("envfiles/login.test.dev.local-it.cloud.env"),  # authentik
+        Path("envfiles/login.test.dev.local-it.cloud.env"),  # authentik
+    ]
+    RUNNER_DICT_COPY = RUNNER_DICT.copy()
+    del RUNNER_DICT_COPY["wordpress"]
+    with pytest.raises(AssertionError) as excinfo:
+        EnvManager(env_paths_list, RUNNER_DICT_COPY)
+    assert "no runner for" in str(excinfo.value)