diff --git a/resources/styles/ext.networknotice.Notice.less b/resources/styles/ext.networknotice.Notice.less
index c38c8c1..5d28365 100644
--- a/resources/styles/ext.networknotice.Notice.less
+++ b/resources/styles/ext.networknotice.Notice.less
@@ -19,7 +19,7 @@
 		background-color: #26292d;
 	}
 
-	&:before {
+	&::before {
 		content: '';
 		width: 0.5rem;
 		top: 0;