diff --git a/Gruntfile.js b/Gruntfile.js
index ab56358b8f60d..7b2b65b43e7f2 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -55,29 +55,34 @@ module.exports = function(grunt) {
 			'!wp-includes/js/dist/vendor/react-jsx-runtime*',
 		],
 
-		// Files sourced from the Gutenberg repository built asset that are ignored by version control.
+		/*
+		 * Files sourced from the Gutenberg repository built asset that are ignored by version control.
+		 *
+		 * Paths are relative to a build root (src/ or build/). The root is applied in the
+		 * clean:gutenberg task so these can be cleaned from src/ and/or build/ as needed.
+		 */
 		gutenbergUnversionedFiles = [
-			SOURCE_DIR + 'wp-includes/blocks/*/*.css',
-			SOURCE_DIR + 'wp-includes/css/dist',
-			SOURCE_DIR + 'wp-includes/js/dist/*.js',
-			SOURCE_DIR + 'wp-includes/js/dist/script-modules',
-			SOURCE_DIR + 'wp-includes/js/dist/vendor/react-jsx-runtime*',
+			'wp-includes/blocks/*/*.css',
+			'wp-includes/css/dist',
+			'wp-includes/js/dist/*.js',
+			'wp-includes/js/dist/script-modules',
+			'wp-includes/js/dist/vendor/react-jsx-runtime*',
 		],
 
 		// Files sourced from the Gutenberg repository built asset that are managed through version control.
 		gutenbergVersionedFiles = [
 			// Block assets (block.json, top-level PHP, nested PHP helpers).
-			SOURCE_DIR + 'wp-includes/blocks/*',
-			'!' + SOURCE_DIR + 'wp-includes/blocks/index.php',
-			SOURCE_DIR + 'wp-includes/images/icon-library',
-			SOURCE_DIR + 'wp-includes/theme.json',
-			SOURCE_DIR + 'wp-includes/theme-i18n.json',
+			'wp-includes/blocks/*',
+			'!wp-includes/blocks/index.php',
+			'wp-includes/images/icon-library',
+			'wp-includes/theme.json',
+			'wp-includes/theme-i18n.json',
 			// Routes and pages.
-			SOURCE_DIR + 'wp-includes/build',
+			'wp-includes/build',
 			// PHP manifests generated by gutenberg:copy.
-			SOURCE_DIR + 'wp-includes/assets/icon-library-manifest.php',
-			SOURCE_DIR + 'wp-includes/assets/script-loader-packages.php',
-			SOURCE_DIR + 'wp-includes/assets/script-modules-packages.php',
+			'wp-includes/assets/icon-library-manifest.php',
+			'wp-includes/assets/script-loader-packages.php',
+			'wp-includes/assets/script-modules-packages.php',
 		],
 
 		// All files built by Webpack, in /src or /build.
@@ -275,6 +280,9 @@ module.exports = function(grunt) {
 			 *
 			 * When `clean:gutenberg` is not explicitly called and run through `grunt clean`, only ignored files are
 			 * cleaned.
+			 *
+			 * Gutenberg-sourced files are always cleaned from src/. For production builds (no --dev), they are also
+			 * cleaned from build/ so that files removed upstream do not linger there if a previous build copied them.
 			 */
 			gutenberg: {
 				get src() {
@@ -284,11 +292,19 @@ module.exports = function(grunt) {
 						cli.includes( 'clean' ) &&
 						! cli.includes( 'clean:gutenberg' );
 
-					if ( isBareCleanSweep ) {
-						return gutenbergUnversionedFiles;
-					} else {
-						return gutenbergUnversionedFiles.concat( gutenbergVersionedFiles );
-					}
+					const fileList = isBareCleanSweep
+						? gutenbergUnversionedFiles
+						: gutenbergUnversionedFiles.concat( gutenbergVersionedFiles );
+
+					const targetDirs = grunt.option( 'dev' )
+						? [ SOURCE_DIR ]
+						: [ SOURCE_DIR, BUILD_DIR ];
+
+					return targetDirs.flatMap( function( dir ) {
+						return fileList.map( function( file ) {
+							return setFilePath( dir, file );
+						} );
+					} );
 				},
 			},