diff --git a/phpBB/styles/prosilver/theme/forms.css b/phpBB/styles/prosilver/theme/forms.css
index 3f85aa3099..803c608bcf 100644
--- a/phpBB/styles/prosilver/theme/forms.css
+++ b/phpBB/styles/prosilver/theme/forms.css
@@ -262,7 +262,7 @@ fieldset.submit-buttons input {
 
 #message-box textarea {
 	font-family: "Trebuchet MS", Verdana, Helvetica, Arial, sans-serif;
-	width: 700px;
+	width: 450px;
 	height: 270px;
 	min-width: 100%;
 	max-width: 100%;