diff --git a/gutenberg.php b/gutenberg.php
index 63aa4b8b0fef02..2e0325cbd3ce19 100644
--- a/gutenberg.php
+++ b/gutenberg.php
@@ -109,7 +109,7 @@ function gutenberg_build_files_notice() {
  * @since 1.5.0
  */
 function gutenberg_pre_init() {
-	if ( GUTENBERG_DEVELOPMENT_MODE && ! file_exists( dirname( __FILE__ ) . '/blocks/build' ) ) {
+	if ( defined( 'GUTENBERG_DEVELOPMENT_MODE' ) && GUTENBERG_DEVELOPMENT_MODE && ! file_exists( dirname( __FILE__ ) . '/blocks/build' ) ) {
 		add_action( 'admin_notices', 'gutenberg_build_files_notice' );
 		return;
 	}