diff --git a/tests/conftest.py b/tests/conftest.py
index 8311d550..9649883b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,3 +1,4 @@
+import random as rand
 from collections.abc import Mapping
 from pathlib import Path
 from typing import Callable
@@ -29,6 +30,13 @@ def patch_broadcast_compat_data():
         yield
 
 
+@fixture(autouse=True)
+def random():
+    """Set random seed for all tests to make them reproducible."""
+    rand.seed(123)
+    np.random.seed(123)
+
+
 def compare_df(
     expected: DataFrame,
     actual: DataFrame,