diff --git a/wp-includes/media.php b/wp-includes/media.php
index 49950b19ba..70f6af5122 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -609,9 +609,14 @@ function wp_get_attachment_image($attachment_id, $size = 'thumbnail', $icon = fa
 		$default_attr = array(
 			'src'	=> $src,
 			'class'	=> "attachment-$size",
-			'alt'	=> trim(strip_tags( $attachment->post_excerpt )),
+			'alt'	=> trim(strip_tags( get_post_meta($attachment_id, '_wp_attachment_image_alt', true) )), // Use Alt field first
 			'title'	=> trim(strip_tags( $attachment->post_title )),
 		);
+		if ( empty($default_attr['alt']) )
+			$default_attr['alt'] = trim(strip_tags( $attachment->post_excerpt )); // If not, Use the Caption
+		if ( empty($default_attr['alt']) )
+			$default_attr['alt'] = trim(strip_tags( $attachment->post_title )); // Finally, use the title
+
 		$attr = wp_parse_args($attr, $default_attr);
 		$attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment );
 		$attr = array_map( 'esc_attr', $attr );