diff --git a/phpBB/adm/style/admin.css b/phpBB/adm/style/admin.css
index 3c7e378b2b..7ef74e4db0 100644
--- a/phpBB/adm/style/admin.css
+++ b/phpBB/adm/style/admin.css
@@ -1572,7 +1572,7 @@ input.button1:focus, input.button2:focus, input.button3:focus {
 	top: 150px;
 	left: 0;
 	right: 0;
-	max-width: 600px;
+	width: 620px;
 	margin: 0 auto;
 	z-index: 50;
 	padding: 25px;
@@ -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 84f6859936..d19b967771 100644
--- a/phpBB/styles/prosilver/theme/common.css
+++ b/phpBB/styles/prosilver/theme/common.css
@@ -812,16 +812,15 @@ li.pagination ul {
 ---------------------------------------- */
 .phpbb_alert {
 	border: 1px solid transparent;
-	position: fixed;
 	display: none;
-	top: 150px;
-	left: 0;
-	right: 0;
-	max-width: 640px;
-	margin: 0 auto;
-	z-index: 50;
-	padding: 25px;
+	left: 0; 
 	padding: 0 25px 20px 25px;
+	position: fixed;
+	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)
diff --git a/phpBB/styles/prosilver/theme/responsive.css b/phpBB/styles/prosilver/theme/responsive.css
index a6bc52db52..7e4caf5301 100644
--- a/phpBB/styles/prosilver/theme/responsive.css
+++ b/phpBB/styles/prosilver/theme/responsive.css
@@ -495,8 +495,8 @@ fieldset.display-actions {
 }
 
 .phpbb_alert {
-	max-width: none;
-	margin: 0 25px;
+	width: auto;
+	margin: 0 5px;
 }
 
 .attach-comment dfn {