diff --git a/test-requirements.txt b/test-requirements.txt
index 5070e93b1..a2fb1cc89 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -9,7 +9,7 @@ mock>=1.2 # BSD
 
 # Backends
 redis>=2.10.0 # MIT
-pymongo>=3.0.2 # Apache-2.0
+pymongo!=3.1,>=3.0.2 # Apache-2.0
 websocket-client>=0.32.0 # LGPLv2+
 
 # Unit testing