diff --git a/src/wp-includes/class-wp-user-query.php b/src/wp-includes/class-wp-user-query.php
index 3d6b28bcc3..050b2822f6 100644
--- a/src/wp-includes/class-wp-user-query.php
+++ b/src/wp-includes/class-wp-user-query.php
@@ -285,7 +285,11 @@ class WP_User_Query {
 		);
 
 		if ( is_array( $qv['fields'] ) ) {
-			$qv['fields'] = array_unique( $qv['fields'] );
+			$qv['fields'] = array_intersect( array_unique( $qv['fields'] ), $allowed_fields );
+
+			if ( empty( $qv['fields'] ) ) {
+				$qv['fields'] = array( 'ID' );
+			}
 
 			$this->query_fields = array();
 			foreach ( $qv['fields'] as $field ) {
@@ -293,8 +297,10 @@ class WP_User_Query {
 				$this->query_fields[] = "$wpdb->users.$field";
 			}
 			$this->query_fields = implode( ',', $this->query_fields );
-		} elseif ( ! in_array( $qv['fields'], $allowed_fields, true ) ) {
+		} elseif ( 'all' === $qv['fields'] ) {
 			$this->query_fields = "$wpdb->users.*";
+		} elseif ( ! in_array( $qv['fields'], $allowed_fields, true ) ) {
+			$this->query_fields = "$wpdb->users.ID";
 		} else {
 			$field              = 'ID' === $qv['fields'] ? 'ID' : sanitize_key( $qv['fields'] );
 			$this->query_fields = "$wpdb->users.$field";
diff --git a/tests/phpunit/tests/user/query.php b/tests/phpunit/tests/user/query.php
index 4ee93ae167..eac4efd7a7 100644
--- a/tests/phpunit/tests/user/query.php
+++ b/tests/phpunit/tests/user/query.php
@@ -1982,8 +1982,8 @@ class Tests_User_Query extends WP_UnitTestCase {
 	public function test_returning_fields( $field, $expected_values ) {
 		$q       = new WP_User_Query(
 			array(
-				'fields'   => $field,
-				'include ' => array( self::$admin_ids[0] ),
+				'fields'  => $field,
+				'include' => array( '1' ),
 			)
 		);
 		$results = $q->get_results();
@@ -2007,68 +2007,94 @@ class Tests_User_Query extends WP_UnitTestCase {
 
 	public function data_returning_fields() {
 		return array(
-			'all'           => array(
+			'all'             => array(
 				'field'    => 'all',
 				'expected' => array(
 					'ID'                  => '1',
 					'user_login'          => 'admin',
 					'user_nicename'       => 'admin',
-					'user_email'          => 'admin@example.org',
-					'user_url'            => 'http://example.org',
+					'user_email'          => WP_TESTS_EMAIL,
+					'user_url'            => wp_guess_url(),
 					'user_activation_key' => '',
 					'user_status'         => '0',
 					'display_name'        => 'admin',
 				),
 			),
-			'all_with_meta' => array(
+			'all_with_meta'   => array(
 				'field'    => 'all_with_meta',
 				'expected' => array(
 					'ID'                  => '1',
 					'user_login'          => 'admin',
 					'user_nicename'       => 'admin',
-					'user_email'          => 'admin@example.org',
-					'user_url'            => 'http://example.org',
+					'user_email'          => WP_TESTS_EMAIL,
+					'user_url'            => wp_guess_url(),
 					'user_activation_key' => '',
 					'user_status'         => '0',
 					'display_name'        => 'admin',
 				),
 			),
-			'ID'            => array(
+			'ID'              => array(
 				'field'    => 'ID',
 				'expected' => array(
 					'ID' => '1',
 				),
 			),
-			'display_name'  => array(
+			'id'              => array(
+				'field'    => 'id',
+				'expected' => array(
+					'ID' => '1',
+				),
+			),
+			'display_name'    => array(
 				'field'    => 'display_name',
 				'expected' => array(
 					'display_name' => 'admin',
 				),
 			),
-			'user_login'    => array(
+			'user_login'      => array(
 				'field'    => 'user_login',
 				'expected' => array(
 					'user_login' => 'admin',
 				),
 			),
-			'user_nicename' => array(
+			'user_nicename'   => array(
 				'field'    => 'user_nicename',
 				'expected' => array(
 					'user_nicename' => 'admin',
 				),
 			),
-			'user_email'    => array(
+			'user_email'      => array(
 				'field'    => 'user_email',
 				'expected' => array(
-					'user_email' => 'admin@example.org',
+					'user_email' => WP_TESTS_EMAIL,
 				),
 			),
-			'invalid_field' => array(
+			'invalid_field'   => array(
 				'field'    => 'invalid_field',
 				'expected' => array(
 					'0' => '1',
 				),
 			),
+			'valid_array'     => array(
+				'field'    => array( 'ID', 'display_name' ),
+				'expected' => array(
+					'ID'           => '1',
+					'display_name' => 'admin',
+				),
+			),
+			'semivalid_array' => array(
+				'field'    => array( 'ID', 'display_name', 'invalid_field' ),
+				'expected' => array(
+					'ID'           => '1',
+					'display_name' => 'admin',
+				),
+			),
+			'invalid_array'   => array(
+				'field'    => array( 'invalid_field' ),
+				'expected' => array(
+					'ID' => '1',
+				),
+			),
 		);
 	}