diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 81738b5c3d..bb7a57f4b5 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -599,7 +599,7 @@ function media_sideload_image($file, $post_id, $desc = null) {
 
 		// Set variables for storage
 		// fix file filename for query strings
-		preg_match('/[^\?]+\.(jpg|JPG|jpe|JPE|jpeg|JPEG|gif|GIF|png|PNG)/', $file, $matches);
+		preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );
 		$file_array['name'] = basename($matches[0]);
 		$file_array['tmp_name'] = $tmp;
 
diff --git a/wp-admin/press-this.php b/wp-admin/press-this.php
index 9d88369c3f..9a6181673a 100644
--- a/wp-admin/press-this.php
+++ b/wp-admin/press-this.php
@@ -172,7 +172,7 @@ if ( !empty($_REQUEST['ajax']) ) {
 		 */
 		function get_images_from_uri($uri) {
 			$uri = preg_replace('/\/#.+?$/','', $uri);
-			if ( preg_match('/\.(jpg|jpe|jpeg|png|gif)$/', $uri) && !strpos($uri,'blogger.com') )
+			if ( preg_match( '/\.(jpe?g|jpe|gif|png)\b/i', $uri ) && !strpos( $uri, 'blogger.com' ) )
 				return "'" . esc_attr( html_entity_decode($uri) ) . "'";
 			$content = wp_remote_fopen($uri);
 			if ( false === $content )
diff --git a/wp-includes/post.php b/wp-includes/post.php
index 1841590860..ea4f3d6711 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4036,7 +4036,7 @@ function wp_attachment_is_image( $post_id = 0 ) {
 
 	$ext = preg_match('/\.([^.]+)$/', $file, $matches) ? strtolower($matches[1]) : false;
 
-	$image_exts = array('jpg', 'jpeg', 'gif', 'png');
+	$image_exts = array( 'jpg', 'jpeg', 'jpe', 'gif', 'png' );
 
 	if ( 'image/' == substr($post->post_mime_type, 0, 6) || $ext && 'import' == $post->post_mime_type && in_array($ext, $image_exts) )
 		return true;