diff --git a/themes/danbooru/comment.theme.php b/themes/danbooru/comment.theme.php
index 6ded3725..ca392da1 100644
--- a/themes/danbooru/comment.theme.php
+++ b/themes/danbooru/comment.theme.php
@@ -97,7 +97,7 @@ class CustomCommentListTheme extends CommentListTheme {
 	 * @param bool $trim
 	 * @return string
 	 */
-	protected function comment_to_html($comment, $trim=false) {
+	protected function comment_to_html(Comment $comment, $trim=false) {
 		global $user;
 
 		$tfe = new TextFormattingEvent($comment->comment);
diff --git a/themes/danbooru2/comment.theme.php b/themes/danbooru2/comment.theme.php
index 826c87d4..224f4c77 100644
--- a/themes/danbooru2/comment.theme.php
+++ b/themes/danbooru2/comment.theme.php
@@ -87,7 +87,7 @@ class CustomCommentListTheme extends CommentListTheme {
 	}
 
 
-	protected function comment_to_html($comment, $trim=false) {
+	protected function comment_to_html(Comment $comment, $trim=false) {
 		global $user;
 
 		$tfe = new TextFormattingEvent($comment->comment);
diff --git a/themes/futaba/comment.theme.php b/themes/futaba/comment.theme.php
index 3406a1d5..29e0b157 100644
--- a/themes/futaba/comment.theme.php
+++ b/themes/futaba/comment.theme.php
@@ -56,7 +56,7 @@ class CustomCommentListTheme extends CommentListTheme {
 	}
 
 
-	protected function comment_to_html($comment, $trim=false) {
+	protected function comment_to_html(Comment $comment, $trim=false) {
 		$inner_id = $this->inner_id; // because custom themes can't add params, because PHP
 		global $user;
 
diff --git a/themes/lite/comment.theme.php b/themes/lite/comment.theme.php
index a30e086b..2cda33c3 100644
--- a/themes/lite/comment.theme.php
+++ b/themes/lite/comment.theme.php
@@ -6,7 +6,7 @@ class CustomCommentListTheme extends CommentListTheme {
 	 * @param bool $trim
 	 * @return string
 	 */
-	protected function comment_to_html($comment, $trim=false) {
+	protected function comment_to_html(Comment $comment, $trim=false) {
 		return $this->rr(parent::comment_to_html($comment, $trim));
 	}