diff --git a/README.md b/README.md
index 4c968b6..9e69f35 100644
--- a/README.md
+++ b/README.md
@@ -100,24 +100,6 @@ $ go get -u github.com/kyoshidajp/tosa
 1. Put `tosa` where you want.
 1. Add `tosa` path to `$PATH`.
 
-## Configuration
-
-### Browser
-
-Add `browser` in `$HOME/.config/tosa`(which is YAML format). Like this.
-
-```
-github.com:
-- user: your_account
-  oauth_token: your_oauth_token
-  protocol: https
-  browser: firefox
-```
-
-This config file is automatically generated when running without setting environment variable `GITHUB_TOKEN`.
-
-The value is a name or an absolute path. By default, used your system default browser.
-
 ## Author
 
 [Katsuhiko YOSHIDA](https://github.com/kyoshidajp)
diff --git a/cli.go b/cli.go
index 2909791..ba43729 100644
--- a/cli.go
+++ b/cli.go
@@ -32,7 +32,6 @@ const (
 	ExitCodeParseFlagsError
 	ExitCodeBadArgs
 	ExitCodePullRequestNotFound
-	ExitCodeOpenPageError
 )
 
 // Debugf prints debug output when EnvDebug is given
@@ -167,23 +166,12 @@ func openPr(client *APIClient, sha string) int {
 		return ExitCodePullRequestNotFound
 	}
 
-	browser, err := GetBrowser()
-	if err != nil {
-		return ExitCodeOpenPageError
-	}
-	Debugf("browser: %s", browser)
-
 	url := *pr.HTMLURL
 	Debugf("URL: %s", url)
 
-	var openErr error
-	if browser == "" {
-		openErr = open.Run(url)
-	} else {
-		openErr = open.RunWith(url, browser)
-	}
+	openErr := open.Run(url)
 	if openErr != nil {
-		PrintErrorf("Could not open page. Check your browser and URL.")
+		PrintErrorf("Could not open page.")
 		return ExitCodeError
 	}