diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 28d551966..336ba6e6f 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -225,6 +225,16 @@ kbd {
 	box-shadow: inset 0 -1px 0 <<colour muted-foreground>>;
 }
 
+::selection {
+	background-color: <<colour primary>>;
+	color: <<colour page-background>>;
+}
+
+::-moz-selection {
+	background-color: <<colour primary>>;
+	color: <<colour page-background>>;
+}
+
 /*
 Markdown likes putting code elements inside pre elements
 */
@@ -2726,4 +2736,4 @@ select {
 
 .tc-fill-background {
 	fill: <<colour background>>;
-}
\ No newline at end of file
+}