diff --git a/tox.ini b/tox.ini
index c463aa2..26c03b7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,6 +18,6 @@ deps =
     pytest==3.6.0
     six==1.16.0
     freezegun==1.2.2
-    fixtures=4.1.0
+    fixtures==4.1.0
 
 commands = pytest -v tests/test_base.py --cov sentry_telegram_py3 --cov-config .coveragerc --cov-report xml