diff --git a/plugins/check_graphite.py b/plugins/check_graphite.py
index 0a42880..a27672d 100755
--- a/plugins/check_graphite.py
+++ b/plugins/check_graphite.py
@@ -82,6 +82,9 @@ def check_graphite(args):
     if len(dps) > 0 and not all_null:
       print "OK: query %s retrieved %d elements" % (query, len(jsonres[0]['datapoints']))
       return STATE_OK
+    if all_null:
+      print "Failed: query %s returned all null values" % (query)
+      return STATE_CRITICAL
 
   print "Failed: query %s returned %s" % (query, result)