diff --git a/README.md b/README.md
index 4366c12..0f916dc 100644
--- a/README.md
+++ b/README.md
@@ -104,7 +104,7 @@ By default, GoTTY doesn't allow clients to send any keystrokes or commands excep
 
 To restrict client access, you can use the `-c` option to enable the basic authentication. With this option, clients need to input the specified username and password to connect to the GoTTY server. Note that the credentials will be transmitted between the server and clients in plain text. For more strict authentication, consider the SSL/TLS client certificate authentication described below.
 
-The `-r` option is a little bit casualer way to restrict access. With this option, GoTTY generates a random URL so that only people who know the URL can get access to the server.  
+The `-r` option is a little bit more casual way to restrict access. With this option, GoTTY generates a random URL so that only people who know the URL can get access to the server.
 
 All traffic between the server and clients are NOT encrypted by default. When you send secret information through GoTTY, we strongly recommend you use the `-t` option which enables TLS/SSL on the session. By default, GoTTY loads the crt and key files placed at `~/.gotty.crt` and `~/.gotty.key`. You can overwrite these file paths with the `--tls-crt` and `--tls-key` options. When you need to generate a self-signed certification file, you can use the `openssl` command.
 
diff --git a/README.md.in b/README.md.in
index 6f96599..714d1a4 100644
--- a/README.md.in
+++ b/README.md.in
@@ -77,7 +77,7 @@ By default, GoTTY doesn't allow clients to send any keystrokes or commands excep
 
 To restrict client access, you can use the `-c` option to enable the basic authentication. With this option, clients need to input the specified username and password to connect to the GoTTY server. Note that the credentials will be transmitted between the server and clients in plain text. For more strict authentication, consider the SSL/TLS client certificate authentication described below.
 
-The `-r` option is a little bit casualer way to restrict access. With this option, GoTTY generates a random URL so that only people who know the URL can get access to the server.  
+The `-r` option is a little bit more casual way to restrict access. With this option, GoTTY generates a random URL so that only people who know the URL can get access to the server.
 
 All traffic between the server and clients are NOT encrypted by default. When you send secret information through GoTTY, we strongly recommend you use the `-t` option which enables TLS/SSL on the session. By default, GoTTY loads the crt and key files placed at `~/.gotty.crt` and `~/.gotty.key`. You can overwrite these file paths with the `--tls-crt` and `--tls-key` options. When you need to generate a self-signed certification file, you can use the `openssl` command.