diff --git a/phpBB/includes/bbcode.php b/phpBB/includes/bbcode.php
index 683fbf0fd2..7b5d8449b3 100644
--- a/phpBB/includes/bbcode.php
+++ b/phpBB/includes/bbcode.php
@@ -404,7 +404,7 @@ class bbcode
 				'i_close'	=> '</span>',
 				'u_open'	=> '<span style="text-decoration: underline">',
 				'u_close'	=> '</span>',
-				'img'		=> '<img src="$1" alt="' . $user->lang['IMAGE'] . '" />',
+				'img'		=> '<img src="$1" class="postimage" alt="' . $user->lang['IMAGE'] . '" />',
 				'size'		=> '<span style="font-size: $1%; line-height: normal">$2</span>',
 				'color'		=> '<span style="color: $1">$2</span>',
 				'email'		=> '<a href="mailto:$1">$2</a>'
diff --git a/phpBB/styles/prosilver/template/attachment.html b/phpBB/styles/prosilver/template/attachment.html
index 4c0a326f1e..c227e710b1 100644
--- a/phpBB/styles/prosilver/template/attachment.html
+++ b/phpBB/styles/prosilver/template/attachment.html
@@ -6,7 +6,7 @@
 
 		<!-- IF _file.S_THUMBNAIL -->
 		<dl class="thumbnail">
-			<dt><a href="{_file.U_DOWNLOAD_LINK}"><img src="{_file.THUMB_IMAGE}" alt="{_file.DOWNLOAD_NAME}" title="{_file.DOWNLOAD_NAME} ({_file.FILESIZE} {_file.SIZE_LANG}) {_file.L_DOWNLOAD_COUNT}" /></a></dt>
+			<dt><a href="{_file.U_DOWNLOAD_LINK}"><img src="{_file.THUMB_IMAGE}" class="postimage" alt="{_file.DOWNLOAD_NAME}" title="{_file.DOWNLOAD_NAME} ({_file.FILESIZE} {_file.SIZE_LANG}) {_file.L_DOWNLOAD_COUNT}" /></a></dt>
 			<!-- IF _file.COMMENT --><dd> {_file.COMMENT}</dd><!-- ENDIF -->
 		</dl>
 		<!-- ENDIF -->
@@ -14,7 +14,7 @@
 
 		<!-- IF _file.S_IMAGE -->
 		<dl class="file">
-			<dt class="attach-image"><img src="{_file.U_INLINE_LINK}" alt="{_file.DOWNLOAD_NAME}" onclick="viewableArea(this);" /></dt>
+			<dt class="attach-image"><img src="{_file.U_INLINE_LINK}" class="postimage" alt="{_file.DOWNLOAD_NAME}" onclick="viewableArea(this);" /></dt>
 			<!-- IF _file.COMMENT --><dd><em>{_file.COMMENT}</em></dd><!-- ENDIF -->
 			<dd>{_file.DOWNLOAD_NAME} ({_file.FILESIZE} {_file.SIZE_LANG}) {_file.L_DOWNLOAD_COUNT}</dd>
 		</dl>
diff --git a/phpBB/styles/prosilver/template/bbcode.html b/phpBB/styles/prosilver/template/bbcode.html
index 909c09df5a..3e38d13a32 100644
--- a/phpBB/styles/prosilver/template/bbcode.html
+++ b/phpBB/styles/prosilver/template/bbcode.html
@@ -31,7 +31,7 @@
 
 <!-- BEGIN size --><span style="font-size: {SIZE}%; line-height: 116%;">{TEXT}</span><!-- END size -->
 
-<!-- BEGIN img --><img src="{URL}" alt="{L_IMAGE}" /><!-- END img -->
+<!-- BEGIN img --><img src="{URL}" class="postimage" alt="{L_IMAGE}" /><!-- END img -->
 
 <!-- BEGIN url --><a href="{URL}" class="postlink">{DESCRIPTION}</a><!-- END url -->
 
diff --git a/phpBB/styles/prosilver/theme/content.css b/phpBB/styles/prosilver/theme/content.css
index 33b97a0814..082016252f 100644
--- a/phpBB/styles/prosilver/theme/content.css
+++ b/phpBB/styles/prosilver/theme/content.css
@@ -273,6 +273,10 @@ div[class].topic-actions {
 	overflow-x: auto;
 }
 
+.postbody img.postimage {
+	max-width: 99%;
+}
+
 .search .postbody {
 	width: 68%
 }
diff --git a/phpBB/styles/subsilver2/template/attachment.html b/phpBB/styles/subsilver2/template/attachment.html
index eb5dd91634..baad7c6cfc 100644
--- a/phpBB/styles/subsilver2/template/attachment.html
+++ b/phpBB/styles/subsilver2/template/attachment.html
@@ -10,12 +10,12 @@
 		<!-- ENDIF -->
 
 		<!-- IF _file.S_THUMBNAIL -->
-			<a href="{_file.U_DOWNLOAD_LINK}"><img src="{_file.THUMB_IMAGE}" alt="{_file.DOWNLOAD_NAME}" /></a><br />
+			<a href="{_file.U_DOWNLOAD_LINK}"><img src="{_file.THUMB_IMAGE}" class="postimage" alt="{_file.DOWNLOAD_NAME}" /></a><br />
 			<span class="gensmall">{_file.DOWNLOAD_NAME} [ {_file.FILESIZE} {_file.SIZE_LANG} | {_file.L_DOWNLOAD_COUNT} ]</span>
 		<!-- ENDIF -->
 
 		<!-- IF _file.S_IMAGE -->
-			<img src="{_file.U_INLINE_LINK}" alt="{_file.DOWNLOAD_NAME}" /><br />
+			<img src="{_file.U_INLINE_LINK}" class="postimage" alt="{_file.DOWNLOAD_NAME}" /><br />
 			<span class="gensmall">{_file.DOWNLOAD_NAME} [ {_file.FILESIZE} {_file.SIZE_LANG} | {_file.L_DOWNLOAD_COUNT} ]</span>
 		<!-- ENDIF -->
 
diff --git a/phpBB/styles/subsilver2/template/bbcode.html b/phpBB/styles/subsilver2/template/bbcode.html
index 5558716cad..9ee5acec34 100644
--- a/phpBB/styles/subsilver2/template/bbcode.html
+++ b/phpBB/styles/subsilver2/template/bbcode.html
@@ -50,7 +50,7 @@
 
 <!-- BEGIN size --><span style="font-size: {SIZE}%; line-height: normal">{TEXT}</span><!-- END size -->
 
-<!-- BEGIN img --><img src="{URL}" alt="{L_IMAGE}" /><!-- END img -->
+<!-- BEGIN img --><img src="{URL}" class="postimage" alt="{L_IMAGE}" /><!-- END img -->
 
 <!-- BEGIN url --><a href="{URL}" class="postlink">{DESCRIPTION}</a><!-- END url -->
 
diff --git a/phpBB/styles/subsilver2/theme/stylesheet.css b/phpBB/styles/subsilver2/theme/stylesheet.css
index 11fc91af0c..0bffc33f37 100644
--- a/phpBB/styles/subsilver2/theme/stylesheet.css
+++ b/phpBB/styles/subsilver2/theme/stylesheet.css
@@ -627,6 +627,10 @@ input:focus, select:focus, textarea:focus {
 	background-color: #FAFAFA;
 }
 
+.postimage {
+	max-width: 99%;
+}
+
 .syntaxbg {
 	color: #FFFFFF;
 }