diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index ae1484f0a..37c49ec56 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -1031,7 +1031,7 @@ button.tc-btn-invisible.tc-remove-tag-button {
 
 	.tc-sidebar-left .tc-sidebar-scrollable {
 		left: 0;
-		right: clamp(calc(<<get.theme.metric storyleft>> + <<get.theme.metric storyminwidth>>),<<get.theme.metric storyright>>,calc(100% - <<get.theme.metric sidebarminwidth>> + <<get.theme.metric storyleft>> + <<get.theme.metric sidebarpadding>>));
+		right: clamp(calc(<<get.theme.metric storyleft>> + <<get.theme.metric storyminwidth>>),<<get.theme.metric storyright>>,calc(100% - <<get.theme.metric sidebarminwidth>> + <<get.theme.metric sidebarpadding>>));
 		margin: 0 -<<get.theme.metric sidebarpadding>> 0 0;
 		z-index: 1;
 	}
@@ -1530,7 +1530,7 @@ html body.tc-body.tc-single-tiddler-window {
 		margin-right: clamp(calc({{$:/themes/tiddlywiki/vanilla/metrics/sidebarminwidth}} - <<get.theme.metric sidebarpadding>>),calc(<<get.theme.metric sidebarwidth>> - <<get.theme.metric sidebarpadding>>),calc(100% - {{$:/themes/tiddlywiki/vanilla/metrics/storyleft}} - {{$:/themes/tiddlywiki/vanilla/metrics/storyminwidth}}));
 	}
 
-	.tc-sidebar-left .tc-story-river {
+	html[dir="rtl"] .tc-sidebar-left .tc-story-river, .tc-sidebar-left .tc-story-river {
 		margin-right: max(0px,{{$:/themes/tiddlywiki/vanilla/metrics/storyleft}});
 		margin-left: clamp(calc({{$:/themes/tiddlywiki/vanilla/metrics/sidebarminwidth}} - <<get.theme.metric sidebarpadding>>),calc(<<get.theme.metric sidebarwidth>> - <<get.theme.metric sidebarpadding>>),calc(100% - {{$:/themes/tiddlywiki/vanilla/metrics/storyleft}} - {{$:/themes/tiddlywiki/vanilla/metrics/storyminwidth}}));
 		left: auto;