diff --git a/histories/models.py b/histories/models.py
index f386eb3..94ddf28 100644
--- a/histories/models.py
+++ b/histories/models.py
@@ -195,6 +195,8 @@ def generate_history(user, ts_start):
     # let's define a new history object.
     history = History(start_ts=ts_start, user=user)
     length = HISTORY_MIN + floor(10 * random.weibullvariate(1, 1.5))
+    history.full_clean()
+    history.save()
 
     history_line = 0
 
@@ -208,4 +210,7 @@ def generate_history(user, ts_start):
                 timestamp=timestamp,
                 history=history
             )
+            new_line.full_clean()
             new_line.save()
+
+    return history