diff --git a/test/runner/requirements/constraints.txt b/test/runner/requirements/constraints.txt
index 03800963ff5..31ae95e7c71 100644
--- a/test/runner/requirements/constraints.txt
+++ b/test/runner/requirements/constraints.txt
@@ -1,4 +1,5 @@
-coverage >= 4.2, != 4.3.2 # features in 4.2+ required, avoid known bug in 4.3.2 on python 2.6
+coverage >= 4.2, != 4.3.2 ; python_version <= '3.7' # features in 4.2+ required, avoid known bug in 4.3.2 on python 2.6
+coverage >= 4.5.4 ; python_version > '3.7' # coverage had a bug in < 4.5.4 that would cause unit tests to hang in Python 3.8
 cryptography < 2.2 ; python_version < '2.7' # cryptography 2.2 drops support for python 2.6
 deepdiff < 4.0.0 ; python_version < '3' # deepdiff 4.0.0 and later require python 3
 urllib3 < 1.24 ; python_version < '2.7' # urllib3 1.24 and later require python 2.7 or later