diff --git a/tests/utils/constraints.txt b/tests/utils/constraints.txt
index 1c04d8152f..395e0096e4 100644
--- a/tests/utils/constraints.txt
+++ b/tests/utils/constraints.txt
@@ -23,6 +23,7 @@ pytest-forked < 1.0.2 ; python_version < '2.7' # pytest-forked 1.0.2 and later r
 pytest-forked >= 1.0.2 ; python_version >= '2.7' # pytest-forked before 1.0.2 does not work with pytest 4.2.0+ (which requires python 2.7+)
 ntlm-auth >= 1.3.0 # message encryption support using cryptography
 requests < 2.20.0 ; python_version < '2.7' # requests 2.20.0 drops support for python 2.6
+requests < 2.28 ; python_version >= '2.7' and python_version < '3.7' # requests 2.28.0 drops support for python 3.6 and before
 requests-ntlm >= 1.1.0 # message encryption support
 requests-credssp >= 0.1.0 # message encryption support
 voluptuous >= 0.11.0 # Schema recursion via Self