diff --git a/tox.ini b/tox.ini
index 343efee..404deb7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -25,7 +25,7 @@ deps =
     oldest: scikit-learn==1.0.1
     oldest: orange3==3.33.0
     oldest: orange-canvas-core==0.1.27
-    oldest: orange-widget-base==4.18.0
+    oldest: orange-widget-base==4.20.0
     latest: https://github.com/biolab/orange3/archive/refs/heads/master.zip#egg=orange3
     latest: https://github.com/biolab/orange-canvas-core/archive/refs/heads/master.zip#egg=orange-canvas-core
     latest: https://github.com/biolab/orange-widget-base/archive/refs/heads/master.zip#egg=orange-widget-base