diff --git a/setup.py b/setup.py
index <HASH>..<HASH> 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@ setup(
         'setuptools_scm',
     ],
     tests_require=[
-        'flake8>=3.7.7,<4',
+        'flake8>=3.7.7,<3.8',
         'pytest>=4.3,<5',
         'pytest-flake8>=1.0.4,<2',
         'responses>=0.9.0,<1',
Suppress interface-breaking flake8 version.