diff --git a/src/wp-includes/class-wp-tax-query.php b/src/wp-includes/class-wp-tax-query.php
index b41f1b238e..38841c42b0 100644
--- a/src/wp-includes/class-wp-tax-query.php
+++ b/src/wp-includes/class-wp-tax-query.php
@@ -598,7 +598,7 @@ class WP_Tax_Query {
 			return;
 		}
 
-		if ( $query['field'] == $resulting_field ) {
+		if ( $query['field'] === $resulting_field ) {
 			return;
 		}