diff --git a/editions/prerelease/tiddlers/sidebarlayout.tid b/editions/prerelease/tiddlers/sidebarlayout.tid
new file mode 100644
index 000000000..2bfa95e13
--- /dev/null
+++ b/editions/prerelease/tiddlers/sidebarlayout.tid
@@ -0,0 +1,3 @@
+title: $:/themes/tiddlywiki/vanilla/options/sidebarlayout
+
+fluid-fixed
\ No newline at end of file
diff --git a/themes/tiddlywiki/vanilla/options.multids b/themes/tiddlywiki/vanilla/options.multids
index d06b052aa..036092379 100644
--- a/themes/tiddlywiki/vanilla/options.multids
+++ b/themes/tiddlywiki/vanilla/options.multids
@@ -1,4 +1,4 @@
 title: $:/themes/tiddlywiki/vanilla/options/
 
 stickytitles: no
-sidebarlayout: fluid-fixed
+sidebarlayout: fixed-fluid