diff --git a/ACU/LDAP.pm b/ACU/LDAP.pm
index 59f0e1f..faeefe1 100644
--- a/ACU/LDAP.pm
+++ b/ACU/LDAP.pm
@@ -145,13 +145,16 @@ sub add_attribute($$$@)
     my @data = $entry->get_value($what);
     for my $value (@_)
     {
-	if (! grep("^$value\$", @data)) {
+	if (! grep { /^\Q$value\E$/ } @data) {
 	    $mod = 1;
 
 	    ACU::Log::do_debug("Add attribute $value to $dn");
 
 	    push @data, $value;
 	}
+	else {
+	    ACU::Log::do_warn("Attribute $what with value $value for $dn already exists.");
+	}
     }
 
     if ($mod)
@@ -160,7 +163,6 @@ sub add_attribute($$$@)
 	my $mesg = $entry->update($ldap) or die $!;
 
 	if ($mesg->code != 0) { ACU::Log::do_warn($mesg->error); return 0; }
-	if ($mesg->count != 1) { ACU::Log::do_warn("$dn not found or multiple entries match"); return 0; }
 
 	return 1;
     }
@@ -181,10 +183,10 @@ sub delete_attribute($$$@)
     my @data = $entry->get_value($what);
     for my $value (@_)
     {
-	if (grep("^$value\$", @data)) {
+	if (grep { /^\Q$value\E$/ } @data) {
 	    ACU::Log::do_debug("Remove attribute $what ($value) from $dn");
 
-	    @data = grep(!"^$value\$", @data);
+	    @data = grep { ! /^\Q$value\E$/ } @data;
 	    $mod = 1;
 	}
 	else {