diff --git a/src/class-wp-import.php b/src/class-wp-import.php
index 57ced62..69195b0 100644
--- a/src/class-wp-import.php
+++ b/src/class-wp-import.php
@@ -895,7 +895,7 @@ function process_posts() {
 							$value = maybe_unserialize( $meta['value'] );
 						}
 
-						add_post_meta( $post_id, wp_slash( $key ), wp_slash_strings_only( $value ) );
+						update_post_meta( $post_id, wp_slash( $key ), wp_slash_strings_only( $value ) );
 
 						do_action( 'import_post_meta', $post_id, $key, $value );