diff --git a/phpBB/styles/prosilver/theme/content.css b/phpBB/styles/prosilver/theme/content.css
index ef18e26ef1..53beee621d 100644
--- a/phpBB/styles/prosilver/theme/content.css
+++ b/phpBB/styles/prosilver/theme/content.css
@@ -514,7 +514,7 @@ blockquote .codebox {
 	height: auto;
 	max-height: 200px;
 	padding-top: 5px;
-	font: 0.9em Monaco, "Andale Mono","Courier New", Courier, mono;
+	font: 0.9em Monaco, "Andale Mono","Courier New", Courier, monospace;
 	line-height: 1.3em;
 	margin: 2px 0;
 }