diff --git a/wp-includes/rewrite.php b/wp-includes/rewrite.php
index 235c0c82..a82c0471 100644
--- a/wp-includes/rewrite.php
+++ b/wp-includes/rewrite.php
@@ -412,7 +412,7 @@ function wp_resolve_numeric_slug_conflicts( $query_vars = array() ) {
 
 	// This is the potentially clashing slug.
 	$value = '';
-	if ( $compare && array_key_exists( $compare, $query_vars ) ) {
+	if ( $compare && array_key_exists( $compare, $query_vars ) && ! is_array( $query_vars[ $compare ] ) ) {
 		$value = $query_vars[ $compare ];
 	}