diff --git a/alibi_detect/utils/visualize.py b/alibi_detect/utils/visualize.py
index de9a4e1b5..4ba8bac76 100644
--- a/alibi_detect/utils/visualize.py
+++ b/alibi_detect/utils/visualize.py
@@ -3,6 +3,7 @@
 import pandas as pd
 from sklearn.metrics import roc_curve, auc
 from typing import Dict, Union
+import warnings
 
 
 def plot_instance_score(preds: Dict,
@@ -79,6 +80,7 @@ def plot_feature_outlier_image(od_preds: Dict,
     instance_ids = instance_ids[:n_instances]
 
     if outliers_only and n_instances == 0:
+        warnings.warn('No outliers found!', UserWarning, stacklevel=3)
         return
 
     n_cols = 2