diff --git a/gulpfile.js b/gulpfile.js
deleted file mode 100644
index dd4259a..0000000
--- a/gulpfile.js
+++ /dev/null
@@ -1,19 +0,0 @@
-'use strict';
-
-const gulp = require('gulp');
-const ts = require('gulp-typescript');
-const es = require('event-stream');
-
-const project = ts.createProject('tsconfig.json');
-
-gulp.task('build', () => {
-	const tsResult = project
-		.src()
-		.pipe(project());
-
-	return es.merge(
-		tsResult.js
-			.pipe(gulp.dest('./built/')),
-		tsResult.dts.pipe(gulp.dest('./built/'))
-	);
-});
diff --git a/package.json b/package.json
index e257f49..85f663f 100644
--- a/package.json
+++ b/package.json
@@ -9,22 +9,16 @@
   "main": "./built/index.js",
   "types": "./built/index.d.ts",
   "scripts": {
-    "build": "gulp build",
+    "build": "tsc",
     "test": "mocha --harmony"
   },
   "devDependencies": {
     "@types/debug": "0.0.29",
     "@types/express": "4.0.35",
     "@types/mocha": "2.2.41",
-    "@types/event-stream": "3.3.31",
-    "@types/gulp": "4.0.2",
-    "@types/gulp-typescript": "0.0.33",
-    "@types/node": "7.0.14",
+    "@types/node": "7.0.15",
     "@types/request": "0.0.42",
-    "event-stream": "3.3.4",
     "express": "4.14.1",
-    "gulp": "3.9.1",
-    "gulp-typescript": "3.1.6",
     "mocha": "3.3.0",
     "typescript": "2.2.2"
   },
diff --git a/src/general.ts b/src/general.ts
index 67be1cf..94cb41a 100644
--- a/src/general.ts
+++ b/src/general.ts
@@ -70,31 +70,37 @@ export default async (url: URL.Url): Promise<Summary> => {
 
 	siteName = siteName ? entities.decode(siteName) : null;
 
-	let icon =
+	const favicon =
 		$('link[rel="shortcut icon"]').attr('href') ||
-		$('link[rel="icon"]').attr('href');
+		$('link[rel="icon"]').attr('href') ||
+		'/favicon.ico';
 
-	if (icon == null) {
-		const favicon = '/favicon.ico';
-
-		const foundFavicon = await new Promise(done => {
-			request.head(URL.resolve(url.href, favicon), (err, res) => {
-				if (err) {
-					done(false);
-				} else if (res.statusCode == 200) {
-					done(true);
-				} else {
-					done(false);
-				}
-			});
+	const checkExistence = (checkURL: string): Promise<string> => new Promise(done => {
+		request.head(checkURL, (err, res) => {
+			if (err) {
+				done(null);
+			} else if (res.statusCode == 200) {
+				done(checkURL);
+			} else {
+				done(null);
+			}
 		});
+	});
 
-		if (foundFavicon) {
-			icon = favicon;
-		}
-	}
+	// 相対的なURL (ex. test) を絶対的 (ex. /test) に変換
+	const toAbsolute = (relativeURLString: string): string => {
+		const relativeURL = URL.parse(relativeURLString);
+		const isAbsolute = relativeURL.slashes || relativeURL.path.indexOf("/") === 0;
+		// 既に絶対的なら、即座に値を返却
+		if (isAbsolute) return relativeURLString;
+		// スラッシュを付けて返却
+		return "/" + relativeURLString;
+	};
 
-	icon = icon ? URL.resolve(url.href, icon) : null;
+	const icon = await checkExistence(URL.resolve(url.href, favicon)) ||
+		// 相対指定を絶対指定に変換し再試行
+		await checkExistence(URL.resolve(url.href, toAbsolute(favicon))) ||
+		null
 
 	if (/[\-—\|:]$/.test(title.replace(new RegExp(`${escapeRegExp(siteName)}$`), '').trim())) {
 		title = title.replace(new RegExp(`${escapeRegExp(siteName)}$`), '').trim();