diff --git a/phpBB/styles/prosilver/template/posting_editor.html b/phpBB/styles/prosilver/template/posting_editor.html
index 70a66be76c..12790360d6 100644
--- a/phpBB/styles/prosilver/template/posting_editor.html
+++ b/phpBB/styles/prosilver/template/posting_editor.html
@@ -47,7 +47,6 @@
 
 	<!-- INCLUDE posting_buttons.html -->
 
-	<div class="smiley-message-box">
 	<div id="smiley-box" class="smiley-box">
 		<!-- EVENT posting_editor_smilies_before -->
 		<!-- IF S_SMILIES_ALLOWED and .smiley -->
@@ -89,7 +88,6 @@
 	</div>
 
 	<!-- EVENT posting_editor_message_after -->
-	</div>	
 	</fieldset>
 
 <!-- IF $EXTRA_POSTING_OPTIONS eq 1 -->
diff --git a/phpBB/styles/prosilver/theme/forms.css b/phpBB/styles/prosilver/theme/forms.css
index 03d32cdadf..ab9ac7a44c 100644
--- a/phpBB/styles/prosilver/theme/forms.css
+++ b/phpBB/styles/prosilver/theme/forms.css
@@ -259,6 +259,9 @@ fieldset.submit-buttons input {
 
 .message-box textarea {
 	font-family: "Trebuchet MS", Verdana, Helvetica, Arial, sans-serif;
+	-webkit-box-sizing: border-box;
+	-moz-box-sizing: border-box;
+	box-sizing: border-box;
 	width: 450px;
 	height: 270px;
 	min-width: 100%;
@@ -284,12 +287,6 @@ fieldset.submit-buttons input {
 	margin: 3px;
 }
 
-.smiley-message-box {
-	display: flex;
-	flex-direction: row-reverse;
-	justify-content: space-between;
-}
-
 /* Input field styles
 ---------------------------------------- */
 .inputbox {
diff --git a/phpBB/styles/prosilver/theme/responsive.css b/phpBB/styles/prosilver/theme/responsive.css
index a8a316ff3b..a53dadc2b7 100644
--- a/phpBB/styles/prosilver/theme/responsive.css
+++ b/phpBB/styles/prosilver/theme/responsive.css
@@ -376,10 +376,6 @@
 		margin-top: 5px;
 	}
 
-	.smiley-message-box {
-		display: block;
-	}
-
 	.bbcode-status {
 		display: none;
 	}