diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 4039fc5de..753016fa6 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -1271,6 +1271,7 @@ canvas.tc-edit-bitmapeditor  {
 	border-left: 1px solid <<colour tab-border>>;
 	-webkit-flex: 1 0 70%;
 	flex: 1 0 70%;
+	overflow: auto; 
 }
 
 .tc-sidebar-lists .tc-tab-buttons {