diff --git a/phpBB/adm/style/ajax.js b/phpBB/adm/style/ajax.js
index 8f7c210e00..8211bdd014 100644
--- a/phpBB/adm/style/ajax.js
+++ b/phpBB/adm/style/ajax.js
@@ -148,6 +148,12 @@ $('[data-ajax]').each(function() {
 	}
 });
 
+/**
+* Automatically resize textarea
+*/
+$(document).ready(function() {
+	phpbb.resizeTextArea($('textarea'), {minHeight: 75});
+});
 
 
 })(jQuery); // Avoid conflicts with other libraries
diff --git a/phpBB/styles/prosilver/template/ajax.js b/phpBB/styles/prosilver/template/ajax.js
index 8dd1f58c97..e7dfe95009 100644
--- a/phpBB/styles/prosilver/template/ajax.js
+++ b/phpBB/styles/prosilver/template/ajax.js
@@ -225,4 +225,13 @@ $('#member_search').click(function () {
 	return false;
 });
 
+/**
+* Automatically resize textarea
+*/
+$(document).ready(function() {
+	phpbb.resizeTextArea($('textarea:not(#message-box textarea)'), {minHeight: 75, maxHeight: 250});
+	phpbb.resizeTextArea($('#message-box textarea'));
+});
+
+
 })(jQuery); // Avoid conflicts with other libraries