diff --git a/wp-includes/post.php b/wp-includes/post.php
index d999c7bfeb..b434ae52e4 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4142,6 +4142,8 @@ function wp_insert_post( $postarr, $wp_error = false, $fire_after_hooks = true )
 	if ( ! empty( $postarr['post_category'] ) ) {
 		// Filter out empty terms.
 		$post_category = array_filter( $postarr['post_category'] );
+	} elseif ( $update && ! isset( $postarr['post_category'] ) ) {
+		$post_category = $post_before->post_category;
 	}
 
 	// Make sure we set a valid category.
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e55896f474..e8557ce318 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-53882';
+$wp_version = '6.1-alpha-53883';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.