diff --git a/requirements_for_test.txt b/requirements_for_test.txt
index 48e8440f3..84a065e21 100644
--- a/requirements_for_test.txt
+++ b/requirements_for_test.txt
@@ -6,7 +6,7 @@ pytest-env==0.6.2
 pytest-mock==1.10.4
 pytest-cov==2.6.1
 coveralls==1.7.0
-pytest-xdist==1.27.0
+pytest-xdist==1.27.0  # pyup: ignore, version 1.28.0 requires pytest >= 4.4
 freezegun==0.3.11
 requests-mock==1.5.2
 # optional requirements for jsonschema