diff --git a/src/wp-includes/rest-api.php b/src/wp-includes/rest-api.php
index d0066ff0fe..a2e3363951 100644
--- a/src/wp-includes/rest-api.php
+++ b/src/wp-includes/rest-api.php
@@ -45,7 +45,15 @@ function register_rest_route( $namespace, $route, $args = array(), $override = f
 	}
 
 	if ( ! did_action( 'rest_api_init' ) ) {
-		_doing_it_wrong( 'register_rest_route', __( 'REST API routes must be registered on the rest_api_init action.' ), '5.1.0' );
+		_doing_it_wrong(
+			'register_rest_route',
+			sprintf(
+				/* translators: %s: rest_api_init */
+				__( 'REST API routes must be registered on the %s action.' ),
+				'<code>rest_api_init</code>'
+			),
+			'5.1.0'
+		);
 	}
 
 	if ( isset( $args['args'] ) ) {