diff --git a/src/transport/smtp/async_transport.rs b/src/transport/smtp/async_transport.rs
index e61aa2f..c796115 100644
--- a/src/transport/smtp/async_transport.rs
+++ b/src/transport/smtp/async_transport.rs
@@ -353,7 +353,7 @@ impl AsyncSmtpTransportBuilder {
         self
     }
 
-    /// Set the authentication mechanism to use
+    /// Set the authentication credentials to use
     pub fn credentials(mut self, credentials: Credentials) -> Self {
         self.info.credentials = Some(credentials);
         self
diff --git a/src/transport/smtp/transport.rs b/src/transport/smtp/transport.rs
index 2e53787..179d886 100644
--- a/src/transport/smtp/transport.rs
+++ b/src/transport/smtp/transport.rs
@@ -270,7 +270,7 @@ impl SmtpTransportBuilder {
         self
     }
 
-    /// Set the authentication mechanism to use
+    /// Set the authentication credentials to use
     pub fn credentials(mut self, credentials: Credentials) -> Self {
         self.info.credentials = Some(credentials);
         self