diff --git a/src/wp-includes/class-wp-site-query.php b/src/wp-includes/class-wp-site-query.php
index b711422479..774f83ea18 100644
--- a/src/wp-includes/class-wp-site-query.php
+++ b/src/wp-includes/class-wp-site-query.php
@@ -251,7 +251,12 @@ class WP_Site_Query {
 		do_action_ref_array( 'pre_get_sites', array( &$this ) );
 
 		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
-		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
+		$_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );
+
+		// Ignore the $fields argument as the queried result will be the same regardless.
+		unset( $_args['fields'] );
+
+		$key = md5( serialize( $_args ) );
 		$last_changed = wp_cache_get_last_changed( 'sites' );
 
 		$cache_key = "get_sites:$key:$last_changed";
diff --git a/tests/phpunit/tests/multisite/siteQuery.php b/tests/phpunit/tests/multisite/siteQuery.php
index 7a739a537d..e6f958d385 100644
--- a/tests/phpunit/tests/multisite/siteQuery.php
+++ b/tests/phpunit/tests/multisite/siteQuery.php
@@ -661,6 +661,82 @@ class Tests_Multisite_Site_Query extends WP_UnitTestCase {
 
 		$this->assertEqualSets( $expected, $found );
 	}
+
+	/**
+	 * @ticket 41197
+	 */
+	public function test_wp_site_query_cache_with_different_fields_no_count() {
+		global $wpdb;
+		$q                 = new WP_Site_Query();
+		$query_1           = $q->query( array(
+			'fields'     => 'all',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+		) );
+		$number_of_queries = $wpdb->num_queries;
+
+		$query_2 = $q->query( array(
+			'fields'     => 'ids',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+		) );
+
+		$this->assertEquals( $number_of_queries, $wpdb->num_queries );
+	}
+
+	/**
+	 * @ticket 41197
+	 */
+	public function test_wp_site_query_cache_with_different_fields_active_count() {
+		global $wpdb;
+		$q                 = new WP_Site_Query();
+
+		$query_1 = $q->query( array(
+			'fields'     => 'all',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+			'count'      => true,
+		) );
+		$number_of_queries = $wpdb->num_queries;
+
+		$query_2 = $q->query( array(
+			'fields'     => 'ids',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+			'count'      => true,
+		) );
+		$this->assertEquals( $number_of_queries, $wpdb->num_queries );
+	}
+
+	/**
+	 * @ticket 41197
+	 */
+	public function test_wp_site_query_cache_with_same_fields_different_count() {
+		global $wpdb;
+		$q = new WP_Site_Query();
+
+		$query_1 = $q->query( array(
+			'fields'     => 'ids',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+		) );
+
+		$number_of_queries = $wpdb->num_queries;
+
+		$query_2 = $q->query( array(
+			'fields'     => 'ids',
+			'network_id' => self::$network_ids['wordpress.org/'],
+			'number'     => 3,
+			'order'      => 'ASC',
+			'count'      => true,
+		) );
+		$this->assertEquals( $number_of_queries + 1, $wpdb->num_queries );
+	}
 }
 
 endif;