diff --git a/preferences/forms.py b/preferences/forms.py
index 032290e4..cc25c3d6 100644
--- a/preferences/forms.py
+++ b/preferences/forms.py
@@ -398,7 +398,7 @@ class RadiusKeyForm(FormRevMixin, ModelForm):
 
     def save(self, commit=True):
         instance = super().save(commit)
-        instance.switch_set = self.cleaned_data["members"]
+        instance.switch_set.set(self.cleaned_data["members"])
         return instance
 
 
@@ -424,7 +424,7 @@ class SwitchManagementCredForm(FormRevMixin, ModelForm):
 
     def save(self, commit=True):
         instance = super().save(commit)
-        instance.switch_set = self.cleaned_data["members"]
+        instance.switch_set.set(self.cleaned_data["members"])
         return instance
 
 
diff --git a/topologie/forms.py b/topologie/forms.py
index 717cee2c..f270cc51 100644
--- a/topologie/forms.py
+++ b/topologie/forms.py
@@ -225,7 +225,7 @@ class EditModelSwitchForm(FormRevMixin, ModelForm):
 
     def save(self, commit=True):
         instance = super().save(commit)
-        instance.switch_set = self.cleaned_data["members"]
+        instance.switch_set.set(self.cleaned_data["members"])
         return instance
 
 
@@ -266,7 +266,7 @@ class EditSwitchBayForm(FormRevMixin, ModelForm):
 
     def save(self, commit=True):
         instance = super().save(commit)
-        instance.switch_set = self.cleaned_data["members"]
+        instance.switch_set.set(self.cleaned_data["members"])
         return instance