diff --git a/overviewer_core/data/web_assets/overviewer.css b/overviewer_core/data/web_assets/overviewer.css
index 9085557..0ae76e5 100644
--- a/overviewer_core/data/web_assets/overviewer.css
+++ b/overviewer_core/data/web_assets/overviewer.css
@@ -111,7 +111,7 @@ body {
     border: 2px solid #000;
     font-size: 12pt;
     width: 20em;
-    background-colour: #fff;
+    background-color: #fff;
 }
 
 #searchControl>input.inactive {