diff --git a/tests/__init__.py b/tests/__init__.py
index e69de29..0b85b53 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: (c) 2021 Artёm IG <github.com/rtmigo>
+# SPDX-License-Identifier: MIT
+
+import random
+
+# Fixed seed for reproducible test runs.
+random.seed(17)