diff --git a/wp-includes/post-template.php b/wp-includes/post-template.php
index 3e8167076..8e1227303 100644
--- a/wp-includes/post-template.php
+++ b/wp-includes/post-template.php
@@ -944,6 +944,8 @@ function wp_get_attachment_link($id = 0, $size = 'thumbnail', $permalink = false
 		$link_text = esc_attr($text);
 	} elseif ( ( is_int($size) && $size != 0 ) or ( is_string($size) && $size != 'none' ) or $size != false ) {
 		$link_text = wp_get_attachment_image($id, $size, $icon);
+	} else {
+		$link_text = '';
 	}
 
 	if( trim($link_text) == '' )