diff --git a/src/wp-includes/block-editor.php b/src/wp-includes/block-editor.php
index 311deaf256590..c81ab65b9e593 100644
--- a/src/wp-includes/block-editor.php
+++ b/src/wp-includes/block-editor.php
@@ -769,10 +769,8 @@ function block_editor_rest_api_preload( array $preload_paths, $block_editor_cont
 	add_filter(
 		'scriptmoduledata_@wordpress/api-fetch',
 		function ( $data ) use ( $preload_data ) {
-			return array_merge(
-				$data,
-				array( 'preloadData' => $preload_data )
-			);
+			$data['preloadData'] = $preload_data;
+			return $data;
 		}
 	);
 }
diff --git a/src/wp-includes/script-modules.php b/src/wp-includes/script-modules.php
index 80ef13f0a2d8d..3a3076f6c88bb 100644
--- a/src/wp-includes/script-modules.php
+++ b/src/wp-includes/script-modules.php
@@ -129,15 +129,11 @@ function wp_register_default_script_modules(): void {
 	add_filter(
 		'scriptmoduledata_@wordpress/api-fetch',
 		function ( $data ) {
-			return array_merge(
-				$data,
-				array(
-					'rootURL'                             => sanitize_url( get_rest_url() ),
-					'nonce'                               => wp_installing() ? '' : wp_create_nonce( 'wp_rest' ),
-					'shouldRegisterMediaUploadMiddleware' => true,
-					'nonceEndpoint'                       => admin_url( 'admin-ajax.php?action=rest-nonce' ),
-				)
-			);
+			$data['rootURL']                             = sanitize_url( get_rest_url() );
+			$data['nonce']                               = wp_installing() ? '' : wp_create_nonce( 'wp_rest' );
+			$data['shouldRegisterMediaUploadMiddleware'] = true;
+			$data['nonceEndpoint']                       = admin_url( 'admin-ajax.php?action=rest-nonce' );
+			return $data;
 		}
 	);
 }
diff --git a/src/wp-includes/theme-previews.php b/src/wp-includes/theme-previews.php
index 88e992a8cd4aa..b4495af8429c8 100644
--- a/src/wp-includes/theme-previews.php
+++ b/src/wp-includes/theme-previews.php
@@ -57,12 +57,8 @@ function wp_attach_theme_preview_middleware() {
 	add_filter(
 		'scriptmoduledata_@wordpress/api-fetch',
 		function ( $data ) {
-			return array_merge(
-				$data,
-				array(
-					'themePreviewPath' => sanitize_text_field( wp_unslash( $_GET['wp_theme_preview'] ) ),
-				)
-			);
+			$data['themePreviewPath'] = sanitize_text_field( wp_unslash( $_GET['wp_theme_preview'] ) );
+			return $data;
 		}
 	);
 }