diff --git a/phpBB/adm/style/admin.css b/phpBB/adm/style/admin.css
index e60e802eb9..7ef74e4db0 100644
--- a/phpBB/adm/style/admin.css
+++ b/phpBB/adm/style/admin.css
@@ -1642,7 +1642,7 @@ input.button1:focus, input.button2:focus, input.button3:focus {
 @media only screen and (max-width: 700px), only screen and (max-device-width: 700px)
 {
 	.phpbb_alert {
-		max-width: none;
+		width: auto;
 		margin: 0 25px;
 	}
 }
diff --git a/phpBB/styles/prosilver/theme/common.css b/phpBB/styles/prosilver/theme/common.css
index c42183f0b0..d19b967771 100644
--- a/phpBB/styles/prosilver/theme/common.css
+++ b/phpBB/styles/prosilver/theme/common.css
@@ -813,13 +813,14 @@ li.pagination ul {
 .phpbb_alert {
 	border: 1px solid transparent;
 	display: none;
-	left: 25%; 
+	left: 0; 
 	padding: 0 25px 20px 25px;
 	position: fixed;
-	right: 25%; 
+	right: 0; 
 	top: 150px;
 	z-index: 50;
 	width: 620px;
+	margin: 0 auto; 
 }
 
 @media only screen and (max-height: 500px), only screen and (max-device-width: 500px)