diff --git a/nnfwtbn/plot.py b/nnfwtbn/plot.py
index 18de9730f45c51e8d46ddb268d8b809e5003cbf8..c815b3dc62b769034c0c79d08c71a4bdf8a3c15d 100644
--- a/nnfwtbn/plot.py
+++ b/nnfwtbn/plot.py
@@ -263,6 +263,9 @@ def hist(dataframe, variable, bins, stacks, selection=None,
         if isinstance(denominator, int) and stacks[denominator] == stack:
             denominator = stack
 
+    if density:
+        uhepp_obj.y_label = "Events (a.u.)"
+
     uhepp_obj.ratio_label = ratio_label
     if ratio_range:
         uhepp_obj.ratio_min = ratio_range[0]