diff --git a/internal/configuration/settings/serverselection.go b/internal/configuration/settings/serverselection.go
index 0976b026e..9b91c8087 100644
--- a/internal/configuration/settings/serverselection.go
+++ b/internal/configuration/settings/serverselection.go
@@ -150,6 +150,9 @@ func (ss *ServerSelection) validate(vpnServiceProvider string,
 
 	if *ss.PortForwardOnly &&
 		vpnServiceProvider != providers.PrivateInternetAccess {
+		// ProtonVPN also supports port forwarding, but on all their servers, so these
+		// don't have the port forwarding boolean field. As a consequence, we only allow
+		// the use of PortForwardOnly for Private Internet Access.
 		return fmt.Errorf("%w: for VPN service provider %s",
 			ErrPortForwardOnlyNotSupported, vpnServiceProvider)
 	}