diff --git a/flowsint-core/tests/conftest.py b/flowsint-core/tests/conftest.py
index bc39b68..5cd0cfc 100644
--- a/flowsint-core/tests/conftest.py
+++ b/flowsint-core/tests/conftest.py
@@ -17,6 +17,12 @@ def setup_test_environment(monkeypatch):
     # Set a test master key for vault tests
     test_key = "base64:qnHTmwYb+uoygIw9MsRMY22vS5YPchY+QOi/E79GAvM="
     monkeypatch.setenv("MASTER_VAULT_KEY_V1", test_key)
+    # Dummy Neo4j credentials: the Neo4jConnection singleton requires them
+    # at construction, but driver creation is lazy — nothing connects.
+    # Without these, tests silently depend on the developer's local .env.
+    monkeypatch.setenv("NEO4J_URI_BOLT", "bolt://127.0.0.1:7687")
+    monkeypatch.setenv("NEO4J_USERNAME", "neo4j")
+    monkeypatch.setenv("NEO4J_PASSWORD", "test-password")
 
 
 @pytest.fixture(autouse=True)
diff --git a/flowsint-enrichers/tests/conftest.py b/flowsint-enrichers/tests/conftest.py
index be95bac..161ca75 100644
--- a/flowsint-enrichers/tests/conftest.py
+++ b/flowsint-enrichers/tests/conftest.py
@@ -2,6 +2,19 @@ import pytest
 from tests.logger import TestLogger
 
 
+@pytest.fixture(autouse=True)
+def setup_test_environment(monkeypatch):
+    """Set up test environment variables.
+
+    Dummy Neo4j credentials: the Neo4jConnection singleton requires them
+    at construction, but driver creation is lazy — nothing connects.
+    Without these, tests silently depend on the developer's local .env.
+    """
+    monkeypatch.setenv("NEO4J_URI_BOLT", "bolt://127.0.0.1:7687")
+    monkeypatch.setenv("NEO4J_USERNAME", "neo4j")
+    monkeypatch.setenv("NEO4J_PASSWORD", "test-password")
+
+
 @pytest.fixture(autouse=True)
 def mock_logger(monkeypatch):
     """Automatically replace the production Logger with TestLogger for all tests."""