diff --git a/lib/Qpsmtpd/Constants.pm b/lib/Qpsmtpd/Constants.pm
index 9e8867f..b1395eb 100644
--- a/lib/Qpsmtpd/Constants.pm
+++ b/lib/Qpsmtpd/Constants.pm
@@ -2,7 +2,9 @@ package Qpsmtpd::Constants;
 use strict;
 require Exporter;
 
-my (@common) = qw(OK DECLINED DONE DENY DENYSOFT DENYHARD DENYSOFTHARD);
+my (@common) = qw(OK DECLINED DONE DENY DENYSOFT DENYHARD
+                  DENY_DISCONNECT DENYSOFT_DISCONNECT
+                 );
 my (@loglevels) = qw(LOGDEBUG LOGINFO LOGNOTICE LOGWARN LOGERROR LOGCRIT LOGALERT LOGEMERG LOGRADAR);
 
 use vars qw($VERSION @ISA @EXPORT);
@@ -12,8 +14,9 @@ use vars qw($VERSION @ISA @EXPORT);
 use constant OK       => 900;
 use constant DENY     => 901;   # 550
 use constant DENYSOFT => 902;   # 450
-use constant DENYHARD => 903;   # 550 + disconnect
-use constant DENYSOFTHARD => 904; # 450 + disconnect
+use constant DENYHARD => 903;   # 550 + disconnect  (deprecated in 0.29)
+use constant DENY_DISCONNECT     => 903; # 550 + disconnect
+use constant DENYSOFT_DISCONNECT => 904; # 450 + disconnect
 use constant DECLINED => 909;
 use constant DONE     => 910;
 
diff --git a/lib/Qpsmtpd/SMTP.pm b/lib/Qpsmtpd/SMTP.pm
index 4d90235..1b5bb58 100644
--- a/lib/Qpsmtpd/SMTP.pm
+++ b/lib/Qpsmtpd/SMTP.pm
@@ -230,13 +230,13 @@ sub mail {
       $self->log(LOGINFO, "denysoft mail from " . $from->format . " ($msg)");
       $self->respond(450, $msg);
     }
-    elsif ($rc == DENYHARD) {
+    elsif ($rc == DENY_DISCONNECT) {
       $msg ||= $from->format . ', denied';
       $self->log(LOGINFO, "deny mail from " . $from->format . " ($msg)");
       $self->respond(550, $msg);
       $self->disconnect;
     }
-    elsif ($rc == DENYSOFTHARD) {
+    elsif ($rc == DENYSOFT_DISCONNECT) {
       $msg ||= $from->format . ', temporarily denied';
       $self->log(LOGINFO, "denysoft mail from " . $from->format . " ($msg)");
       $self->respond(450, $msg);
@@ -273,13 +273,13 @@ sub rcpt {
     $msg ||= 'relaying denied';
     return $self->respond(450, $msg);
   }
-  elsif ($rc == DENYHARD) {
+  elsif ($rc == DENY_DISCONNECT) {
       $msg ||= 'delivery denied';
       $self->log(LOGINFO, "delivery denied ($msg)");
       $self->respond(550, $msg);
       $self->disconnect;
   }
-  elsif ($rc == DENYSOFTHARD) {
+  elsif ($rc == DENYSOFT_DISCONNECT) {
     $msg ||= 'relaying denied';
     $self->log(LOGINFO, "delivery denied ($msg)");
     $self->respond(450, $msg);