diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 05970af15..f1d942af9 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -702,7 +702,7 @@ button.tc-untagged-label {
 <<if-no-sidebar "
 
 	.tc-story-river {
-		width: auto;
+        width: calc(100% - {{$:/themes/tiddlywiki/vanilla/metrics/storyleft}});
 	}
 
 ">>