diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..e9d42c9
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,10 @@
+import warnings
+
+import pytest
+
+
+@pytest.fixture()
+def treat_warnings_as_error():
+    with warnings.catch_warnings():
+        warnings.simplefilter("error")
+        yield
diff --git a/tests/unit/spectrum/baseline/test_tophat_baseline.py b/tests/unit/spectrum/baseline/test_tophat_baseline.py
index 0df22bd..5cadc9c 100644
--- a/tests/unit/spectrum/baseline/test_tophat_baseline.py
+++ b/tests/unit/spectrum/baseline/test_tophat_baseline.py
@@ -1,5 +1,3 @@
-import warnings
-
 import numpy as np
 import pytest
 
@@ -8,7 +6,7 @@
 
 
 @pytest.fixture(autouse=True)
-def mock_environ(monkeypatch):
+def mock_environ(monkeypatch, treat_warnings_as_error):
     monkeypatch.setenv("NUMBA_DEBUGINFO", "1")
 
 
@@ -27,13 +25,6 @@ def mock_baseline(mock_window_size, mock_window_unit):
     return TophatBaseline(window_size=mock_window_size, window_unit=mock_window_unit)
 
 
-@pytest.fixture(autouse=True)
-def treat_warnings_as_error():
-    with warnings.catch_warnings():
-        warnings.simplefilter("error")
-        yield
-
-
 def test_compute_erosion():
     x = np.array([10, 20, 30, 40, 50, 60, 70, 80, 90, 100], dtype=float)
     element_size = 5