diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
index d249ab81f5..e0cdc79a2f 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -1908,7 +1908,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 					$schema['properties']['format'] = array(
 						'description' => __( 'The format for the object.' ),
 						'type'        => 'string',
-						'enum'        => $supports_formats ? array_values( $supports_formats[0] ) : array(),
+						'enum'        => array_merge( array( 'standard' ), $supports_formats ? array_values( $supports_formats[0] ) : array() ),
 						'context'     => array( 'view', 'edit' ),
 					);
 					break;
diff --git a/tests/phpunit/tests/rest-api/rest-posts-controller.php b/tests/phpunit/tests/rest-api/rest-posts-controller.php
index 0e738c394d..70db2e2bd3 100644
--- a/tests/phpunit/tests/rest-api/rest-posts-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-posts-controller.php
@@ -1287,6 +1287,22 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		$this->assertEquals( 'gallery', get_post_format( $new_post->ID ) );
 	}
 
+	public function test_create_post_with_standard_format() {
+		wp_set_current_user( self::$editor_id );
+
+		$request = new WP_REST_Request( 'POST', '/wp/v2/posts' );
+		$params = $this->set_post_data( array(
+			'format' => 'standard',
+		) );
+		$request->set_body_params( $params );
+		$response = $this->server->dispatch( $request );
+
+		$data = $response->get_data();
+		$new_post = get_post( $data['id'] );
+		$this->assertEquals( 'standard', $data['format'] );
+		$this->assertFalse( get_post_format( $new_post->ID ) );
+	}
+
 	public function test_create_post_with_invalid_format() {
 		wp_set_current_user( self::$editor_id );
 
@@ -1753,6 +1769,22 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		$this->assertEquals( 'gallery', get_post_format( $new_post->ID ) );
 	}
 
+	public function test_update_post_with_standard_format() {
+		wp_set_current_user( self::$editor_id );
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$params = $this->set_post_data( array(
+			'format' => 'standard',
+		) );
+		$request->set_body_params( $params );
+		$response = $this->server->dispatch( $request );
+
+		$data = $response->get_data();
+		$new_post = get_post( $data['id'] );
+		$this->assertEquals( 'standard', $data['format'] );
+		$this->assertFalse( get_post_format( $new_post->ID ) );
+	}
+
 	public function test_update_post_with_invalid_format() {
 		wp_set_current_user( self::$editor_id );