diff --git a/src/PVE/Auth/PAM.pm b/src/PVE/Auth/PAM.pm
index 11750c5..8586da5 100644
--- a/src/PVE/Auth/PAM.pm
+++ b/src/PVE/Auth/PAM.pm
@@ -25,7 +25,7 @@ sub authenticate_user {
     my ($class, $config, $realm, $username, $password) = @_;
 
     # user (www-data) need to be able to read /etc/passwd /etc/shadow
-    die "no password\n" if !defined($password) || $password eq '';
+    die "no password\n" if !$password;
 
     # PAM modules may temporarily override $SIG{CHLD}, causing SIGCHLDs from
     # RESTEnvironment workers to be lost. Running the PAM interaction in a fork