diff --git a/requirements/bench.txt b/requirements/bench.txt
index c593b454d0..5f72ce820f 100644
--- a/requirements/bench.txt
+++ b/requirements/bench.txt
@@ -4,7 +4,7 @@ xlrd>=1.2.0
 lpips==0.1.3
 opencv-python>=4.1.2.30
 matplotlib>=2.2.3
-gym>=0.12.1
+gym>=0.12.1,<0.20.0
 gym-anm>=1.0.1
 torch>=1.7.0
 hiplot