diff --git a/wp-includes/post.php b/wp-includes/post.php
index 2f7cba613f..993056ff2c 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -8094,10 +8094,11 @@ function get_available_post_mime_types( $type = 'attachment' ) {
 	$mime_types = apply_filters( 'pre_get_available_post_mime_types', null, $type );
 
 	if ( ! is_array( $mime_types ) ) {
-		$mime_types = $wpdb->get_col( $wpdb->prepare( "SELECT DISTINCT post_mime_type FROM $wpdb->posts WHERE post_type = %s", $type ) );
+		$mime_types = $wpdb->get_col( $wpdb->prepare( "SELECT DISTINCT post_mime_type FROM $wpdb->posts WHERE post_type = %s AND post_mime_type != ''", $type ) );
 	}
 
-	return $mime_types;
+	// Remove nulls from returned $mime_types.
+	return array_values( array_filter( $mime_types ) );
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 45917072ae..cbf661fdf0 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-beta2-58436';
+$wp_version = '6.6-beta2-58437';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.