diff --git a/modules/realtimepreview/TwoPaneLayout.less b/modules/realtimepreview/TwoPaneLayout.less
index a6c0c976..2f1ba417 100644
--- a/modules/realtimepreview/TwoPaneLayout.less
+++ b/modules/realtimepreview/TwoPaneLayout.less
@@ -21,6 +21,7 @@
 		padding: 0;
 		display: flex;
 		flex-direction: column;
+		min-width: 248px;
 
 		.ext-WikiEditor-realtimepreview-preview {
 			overflow: auto;