diff --git a/test/form/samples/emit-asset-file/_config.js b/test/form/samples/emit-asset-file/_config.js
index b9f1d83de22..f31337dd5a9 100644
--- a/test/form/samples/emit-asset-file/_config.js
+++ b/test/form/samples/emit-asset-file/_config.js
@@ -32,6 +32,16 @@ module.exports = {
 					'asset has correct source'
 				);
 				assert.ok(keys[1].endsWith('.js'), `${keys[1]} ends with ".js"`);
+			},
+			writeBundle(outputBundle) {
+				const keys = Object.keys(outputBundle);
+				const asset = outputBundle[keys[0]];
+				assert.ok(
+					asset.source.equals(
+						fs.readFileSync(path.resolve(__dirname, '_expected', asset.fileName))
+					),
+					'asset has correct source'
+				);
 			}
 		}
 	}