diff --git a/just-rwd-functions.php b/just-rwd-functions.php
index bd34760..2549b9f 100644
--- a/just-rwd-functions.php
+++ b/just-rwd-functions.php
@@ -21,7 +21,10 @@
  * @param string           $tag Specify which tag should be used: picture|img.
  * @param array            $attr  Additional html attributes to be used for main tag.
  */
-function rwd_attachment_image( $attachment = null, $size = 'thumbnail', $tag = 'picture', $attr = array() ) {
+function rwd_attachment_image( $attachment = null, $size = 'thumbnail', $tag = null, $attr = array() ) {
+	if( empty( $tag ) ) {
+		$tag = apply_filters( 'rwd_tag_type', 'picture' );
+	}
 	echo get_rwd_attachment_image( $attachment, $size, $tag, $attr );
 }
 
@@ -41,9 +44,13 @@ function rwd_attachment_image( $attachment = null, $size = 'thumbnail', $tag = '
  *
  * @return string Generated html.
  */
-function get_rwd_attachment_image( $attachment = null, $size = 'thumbnail', $tag = 'picture', $attr = array() ) {
+function get_rwd_attachment_image( $attachment = null, $size = 'thumbnail', $tag = null, $attr = array() ) {
 	$rwd_image = new RwdImage( $attachment );
 
+	if( empty( $tag ) ) {
+		$tag = apply_filters( 'rwd_tag_type', 'picture' );
+	}
+
 	$size = apply_filters( 'post_thumbnail_size', $size );
 
 	if ( 'img' != $tag ) {