diff --git a/includes/class-hashtag.php b/includes/class-hashtag.php
index d1f46e1..a50c6c5 100644
--- a/includes/class-hashtag.php
+++ b/includes/class-hashtag.php
@@ -31,7 +31,7 @@ class Hashtag {
 	 */
 	public static function insert_post( $id, $data ) {
 		if ( preg_match_all( '/' . ACTIVITYPUB_HASHTAGS_REGEXP . '/i', $data->post_content, $match ) ) {
-			$tags = implode( ', ', $match[2] );
+			$tags = implode( ', ', $match[1] );
 
 			wp_add_post_tags( $data->post_parent, $tags );
 		}
@@ -59,16 +59,15 @@ class Hashtag {
 	 * @return string the final string
 	 */
 	public static function replace_with_links( $result ) {
-		$tag = $result[2];
-		$space = $result[1];
-		$tag_object = get_term_by( 'name', $result[2], 'post_tag' );
+		$tag = $result[1];
+		$tag_object = get_term_by( 'name', $result[1], 'post_tag' );
 
 		if ( $tag_object ) {
 			$link = get_term_link( $tag_object, 'post_tag' );
-			return "$space<a href='$link' rel='tag'>#$tag</a>";
+			return sprintf( '<a rel="tag" class="u-tag u-category" href="%s">#%s</a>', $link, $tag );
 		}
 
-		return $space . '#' . $tag;
+		return '#' . $tag;
 	}
 
 	/**
diff --git a/tests/test-class-activitypub-hashtag.php b/tests/test-class-activitypub-hashtag.php
index 5eddeef..bfbacbb 100644
--- a/tests/test-class-activitypub-hashtag.php
+++ b/tests/test-class-activitypub-hashtag.php
@@ -13,6 +13,7 @@ class Test_Activitypub_Hashtag extends WP_UnitTestCase {
 		return [
 			[ 'test', 'test' ],
 			[ '#test', '#test' ],
+			[ 'hallo #test test', 'hallo #test test' ],
 		];
 	}
 }