diff --git a/README.md b/README.md
index b4f4c56..7e9e530 100644
--- a/README.md
+++ b/README.md
@@ -114,13 +114,13 @@ Server Options:
     -m, --message <message>          Notification message
     -t, --token <token>              Notification token
 iOS Options:
-    -i, --pem <file>                 certificate key file path
+    -i, --key <file>                 certificate key file path
     -P, --password <password>        certificate key password
     --topic <topic>                  iOS topic
     --ios                            enabled iOS (default: false)
     --production                     iOS production mode (default: false)
 Android Options:
-    -k, --key <api_key>              Android API Key
+    -k, --apikey <api_key>           Android API Key
     --android                        enabled android (default: false)
 Common Options:
     -h, --help                       Show this message
@@ -148,7 +148,7 @@ $ gorush -ios -m="your message" -i="your certificate path" -t="device token" -to
 ```
 
 * `-m`: Notification message.
-* `-i`: Apple Push Notification Certificate path (`pem` file).
+* `-i`: Apple Push Notification Certificate path (`pem` or `p12` file).
 * `-t`: Device token.
 * `-topic`: The topic of the remote notification.
 * `-password`: The certificate password.
diff --git a/gorush.go b/gorush.go
index 1af4b83..0245142 100644
--- a/gorush.go
+++ b/gorush.go
@@ -30,13 +30,13 @@ Server Options:
     -m, --message <message>          Notification message
     -t, --token <token>              Notification token
 iOS Options:
-    -i, --pem <file>                 certificate key file path
+    -i, --key <file>                 certificate key file path
     -P, --password <password>        certificate key password
     --topic <topic>                  iOS topic
     --ios                            enabled iOS (default: false)
     --production                     iOS production mode (default: false)
 Android Options:
-    -k, --key <api_key>              Android API Key
+    -k, --apikey <api_key>           Android API Key
     --android                        enabled android (default: false)
 Common Options:
     -h, --help                       Show this message
@@ -63,11 +63,11 @@ func main() {
 	flag.StringVar(&configFile, "c", "", "Configuration file.")
 	flag.StringVar(&configFile, "config", "", "Configuration file.")
 	flag.StringVar(&opts.Ios.KeyPath, "i", "", "iOS certificate key file path")
-	flag.StringVar(&opts.Ios.KeyPath, "pem", "", "iOS certificate key file path")
+	flag.StringVar(&opts.Ios.KeyPath, "key", "", "iOS certificate key file path")
 	flag.StringVar(&opts.Ios.Password, "P", "", "iOS certificate password for gorush")
 	flag.StringVar(&opts.Ios.Password, "password", "", "iOS certificate password for gorush")
 	flag.StringVar(&opts.Android.APIKey, "k", "", "Android api key configuration for gorush")
-	flag.StringVar(&opts.Android.APIKey, "key", "", "Android api key configuration for gorush")
+	flag.StringVar(&opts.Android.APIKey, "apikey", "", "Android api key configuration for gorush")
 	flag.StringVar(&opts.Core.Port, "p", "", "port number for gorush")
 	flag.StringVar(&opts.Core.Port, "port", "", "port number for gorush")
 	flag.StringVar(&token, "t", "", "token string")