diff --git a/src/wp-includes/blocks.php b/src/wp-includes/blocks.php
index 58e03d015585c..f5431e29f0751 100644
--- a/src/wp-includes/blocks.php
+++ b/src/wp-includes/blocks.php
@@ -1160,7 +1160,7 @@ function apply_block_hooks_to_content( $content, $context = null, $callback = 'i
  *                               Default: 'insert_hooked_blocks'.
  * @return string The serialized markup.
  */
-function apply_block_hooks_to_content_from_post_object( $content, $post = null, $callback = 'insert_hooked_blocks' ) {
+function apply_block_hooks_to_content_from_post_object( $content, ?WP_Post $post = null, $callback = 'insert_hooked_blocks' ) {
 	// Default to the current post if no context is provided.
 	if ( null === $post ) {
 		$post = get_post();