diff --git a/zmldapsync/zmldapsync.pl b/zmldapsync/zmldapsync.pl
index fc2707a..5314683 100644
--- a/zmldapsync/zmldapsync.pl
+++ b/zmldapsync/zmldapsync.pl
@@ -666,9 +666,11 @@ DOMAIN: foreach my $domain ( keys $conf->{domains} ) {
   }
 }
 
-# zmprov breaks terminal (no echo to your input after execution)
-# fix it with a tset
-system('tset');
+if ( -t STDIN and -t STDOUT ) {
+  # zmprov breaks terminal (no echo to your input after execution)
+  # fix it with a tset
+  system('tset');
+}
 
 # Exit with the global exit code (if at least one domain had an error, it'll be != 0)
 exit $exit;