diff --git a/requirements-test.txt b/requirements-test.txt
index 366de855..9646490a 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,5 +1,5 @@
 # Additional requirements for the unit and coverage tests
 
-coveralls<=1.2.0
+coveralls<=3.3.1  # Last Python 3.6 version
 codecov
 pre-commit