diff --git a/plugins/time/ntpdate_ b/plugins/time/ntpdate_
index 34778c80..bb62d5bd 100755
--- a/plugins/time/ntpdate_
+++ b/plugins/time/ntpdate_
@@ -30,6 +30,7 @@ fi
 
 if [ "$1" = "config" ]; then
   echo "graph_title NTP offset and delay to peer $PEER"
+  echo "graph_category time"
   echo "graph_args --base 1000 --vertical-label msec"
   echo "offset.label Offset"
   echo "offset.draw LINE2"