diff --git a/assets/scss/bergamot.scss b/assets/scss/bergamot.scss
index 9914bc4..1cadc6e 100644
--- a/assets/scss/bergamot.scss
+++ b/assets/scss/bergamot.scss
@@ -51,6 +51,10 @@
         }
     }
 
+    .bergamot-proof-tree {
+        overflow: auto;
+    }
+
     .bergamot-selector {
         button {
             @include var(background-color, background-color);