diff --git a/check_matrix_synapse.py b/check_matrix_synapse.py
index 5ba9eb3..562ab6c 100755
--- a/check_matrix_synapse.py
+++ b/check_matrix_synapse.py
@@ -106,8 +106,8 @@ def main():
     elif args.type == 'db-lag':
         db_lag_MAX = 0.01 if not args.crit else args.crit  # in seconds
         try:
-            db_lag, null_present = get_waiting_for_db(args.grafana_api_key, args.interval, args.range, args.grafana_server)
-            null_warn = 'Null data was present for this timeseries.' if null_present else ''
+            db_lag, null_present, raw_data = get_waiting_for_db(args.grafana_api_key, args.interval, args.range, args.grafana_server)
+            null_warn = f'Null data was present for this timeseries.\n{raw_data}' if null_present else ''
             if db_lag > db_lag_MAX:
                 print(f"CRITICAL: DB lag is {db_lag} sec. {null_warn} |'db-lag'={db_lag}s;;;")
                 sys.exit(nagios.CRITICAL)
diff --git a/checker/synapse_grafana.py b/checker/synapse_grafana.py
index 4cb822b..0e48f6d 100644
--- a/checker/synapse_grafana.py
+++ b/checker/synapse_grafana.py
@@ -310,13 +310,14 @@ def get_waiting_for_db(api_key, interval, data_range, endpoint):
         'to': 'now',
     }
     response = requests.post(f'{endpoint}/api/ds/query', headers={'Authorization': f'Bearer {api_key}'}, json=json_data, verify=False).json()
-    data = response['results']['A']['frames'][0]['data']['values'][1]
+    raw_data = response['results']['A']['frames'][0]['data']['values'][1]
+    data = []
     null_present = False
-    for i in range(len(data)):
-        if data[i] is None:
-            data[i] = -1
+    for i in range(len(raw_data)):
+        if raw_data[i] is not None:
+            data.append(raw_data[i])
             null_present = True
-    return np.round(np.average(data), 5), null_present
+    return np.round(np.average(data), 5), null_present, raw_data
 
 
 def get_stateres_worst_case(api_key, interval, data_range, endpoint):