diff --git a/package.json b/package.json
index 96c7a70..d307296 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "summaly",
-  "version": "1.2.1",
+  "version": "1.2.2",
   "description": "Get web page's summary",
   "author": "syuilo <i@syuilo.com>",
   "license": "MIT",
diff --git a/src/index.ts b/src/index.ts
index 26e3f63..28279c8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -20,9 +20,14 @@ export default async (url: string): Promise<ISummary> => {
 	const summary = plugin
 		? await plugin.summary(_url)
 		: await general(_url);
-	
+
 	Object.keys(summary).forEach(k => {
-		(<any>summary)[k] = (<any>summary)[k].trim();
+		if ((<any>summary)[k]) {
+			(<any>summary)[k] = (<any>summary)[k].trim();
+			if ((<any>summary)[k] == '') {
+				(<any>summary)[k] = null;
+			}
+		}
 	});
 
 	return summary;