diff --git a/apps/wei/forms/surveys/wei2021.py b/apps/wei/forms/surveys/wei2021.py
index 2ff8adcc9681daa2cf06f5f69b0a5c34b82fc63b..eaaba872a471dd1929029587043255d334683963 100644
--- a/apps/wei/forms/surveys/wei2021.py
+++ b/apps/wei/forms/surveys/wei2021.py
@@ -43,28 +43,29 @@ class WEISurveyForm2021(forms.Form):
             registration._force_save = True
             registration.save()
 
-        rng = Random(information.seed)
+        if self.data:
+            self.fields["word"].choices = [(w, w) for w in WORDS]
+            if self.is_valid():
+                return
+
+        rng = Random((information.step + 1) * information.seed)
 
         words = None
-        # Update seed
-        rng.randint(0, information.step)
 
         buses = WEISurveyAlgorithm2021.get_buses()
-        scores = sum((list(WEIBusInformation2021(bus).scores.values()) for bus in buses), [])
+        informations = {bus: WEIBusInformation2021(bus) for bus in buses}
+        scores = sum((list(informations[bus].scores.values()) for bus in buses), [])
         average_score = sum(scores) / len(scores)
 
         preferred_words = {bus: [word for word in WORDS
-                                 if WEIBusInformation2021(bus).scores[word] >= average_score]
+                                 if informations[bus].scores[word] >= average_score]
                            for bus in buses}
         while words is None or len(set(words)) != len(words):
+            print("toto")
             # Ensure that there is no the same word 2 times
             words = [rng.choice(words) for _ignored2, words in preferred_words.items()]
         rng.shuffle(words)
         words = [(w, w) for w in words]
-        if self.data:
-            self.fields["word"].choices = [(w, w) for w in WORDS]
-            if self.is_valid():
-                return
         self.fields["word"].choices = words