diff --git a/src/wp-admin/includes/plugin.php b/src/wp-admin/includes/plugin.php
index f8ca6ea5fd..b8dcdbe53b 100644
--- a/src/wp-admin/includes/plugin.php
+++ b/src/wp-admin/includes/plugin.php
@@ -635,7 +635,9 @@ function activate_plugin( $plugin, $redirect = '', $network_wide = false, $silen
 		ob_start();
 		wp_register_plugin_realpath( WP_PLUGIN_DIR . '/' . $plugin );
 		$_wp_plugin_file = $plugin;
-		define( 'WP_SANDBOX_SCRAPING', true );
+		if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
+			define( 'WP_SANDBOX_SCRAPING', true );
+		}
 		include_once( WP_PLUGIN_DIR . '/' . $plugin );
 		$plugin = $_wp_plugin_file; // Avoid stomping of the $plugin variable in a plugin.
 
@@ -2132,7 +2134,9 @@ function wp_clean_plugins_cache( $clear_update_cache = true ) {
  * @param string $plugin Path to the plugin file relative to the plugins directory.
  */
 function plugin_sandbox_scrape( $plugin ) {
-	define( 'WP_SANDBOX_SCRAPING', true );
+	if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
+		define( 'WP_SANDBOX_SCRAPING', true );
+	}
 	wp_register_plugin_realpath( WP_PLUGIN_DIR . '/' . $plugin );
 	include( WP_PLUGIN_DIR . '/' . $plugin );
 }
diff --git a/src/wp-admin/includes/theme.php b/src/wp-admin/includes/theme.php
index 98391123aa..5283cea8bc 100644
--- a/src/wp-admin/includes/theme.php
+++ b/src/wp-admin/includes/theme.php
@@ -859,7 +859,9 @@ function resume_theme( $theme, $redirect = '' ) {
 
 			// Load the theme's functions.php to test whether it throws a fatal error.
 			ob_start();
-			define( 'WP_SANDBOX_SCRAPING', true );
+			if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
+				define( 'WP_SANDBOX_SCRAPING', true );
+			}
 			include $functions_path;
 			ob_clean();
 		}
diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index 1915fbde17..05d37f5a79 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -1444,7 +1444,9 @@ function wp_start_scraping_edited_file_errors() {
 		echo "###### wp_scraping_result_end:$key ######";
 		die();
 	}
-	define( 'WP_SANDBOX_SCRAPING', true );
+	if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
+		define( 'WP_SANDBOX_SCRAPING', true );
+	}
 	register_shutdown_function( 'wp_finalize_scraping_edited_file_errors', $key );
 }