diff --git a/pyproject.toml b/pyproject.toml
index 2eea56d..2c6e4cc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,7 +58,7 @@ extend-immutable-calls = [
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 testpaths = ["tests"]
-addopts = "--import-mode=prepend"
+addopts = "--import-mode=importlib"
 
 [tool.mypy]
 python_version = "3.11"
diff --git a/tests/unit/test_auth.py b/tests/unit/test_auth.py
index 2e03924..74c7f54 100644
--- a/tests/unit/test_auth.py
+++ b/tests/unit/test_auth.py
@@ -1,5 +1,5 @@
 import pytest
-from fastapi import FastAPI
+from fastapi import FastAPI, Request
 from fastapi.testclient import TestClient
 
 
@@ -59,7 +59,6 @@ def test_invalid_bearer_401():
 
 def test_testnet_token_sets_env_testnet():
     from cerbero_mcp.auth import install_auth_middleware
-    from fastapi import Request
 
     fa = FastAPI()
     install_auth_middleware(fa, testnet_token="tk_test", mainnet_token="tk_live")
@@ -76,7 +75,6 @@ def test_testnet_token_sets_env_testnet():
 
 def test_mainnet_token_sets_env_mainnet():
     from cerbero_mcp.auth import install_auth_middleware
-    from fastapi import Request
 
     fa = FastAPI()
     install_auth_middleware(fa, testnet_token="tk_test", mainnet_token="tk_live")