diff --git a/rdmo/accounts/admin.py b/rdmo/accounts/admin.py
index 1cfede8540..8d65fb1f57 100644
--- a/rdmo/accounts/admin.py
+++ b/rdmo/accounts/admin.py
@@ -30,15 +30,29 @@ class RoleAdmin(admin.ModelAdmin):
 
     list_display = ('user', 'email', 'members', 'managers', 'editors', 'reviewers')
 
+    readonly_fields = ('user', )
+
     def get_queryset(self, request):
         return Role.objects.prefetch_related(
                 'member', 'manager', 'editor', 'reviewer').annotate(
-                    Count('member'), Count('manager'), Count('editor'), Count('reviewer'),
+                    Count('member', distinct=True),
+                    Count('manager', distinct=True),
+                    Count('editor', distinct=True),
+                    Count('reviewer', distinct=True),
                     sites_count=Value(Site.objects.count())
                 )
 
+    def get_form(self, request, obj=None, **kwargs):
+        form = super().get_form(request, obj, **kwargs)
+        form.base_fields['member'].widget.can_add_related = False
+        form.base_fields['manager'].widget.can_add_related = False
+        form.base_fields['editor'].widget.can_add_related = False
+        form.base_fields['reviewer'].widget.can_add_related = False
+
+        return form
+
     @staticmethod
-    def render_all_sites_or_join(obj, field_name: str) -> str:
+    def get_sites_for_role(obj, field_name: str) -> str:
         if getattr(obj, f'{field_name}__count', 0) == obj.sites_count:
             return 'all Sites'
         return ', '.join([site.domain for site in getattr(obj, field_name).all()])
@@ -47,13 +61,13 @@ def email(self, obj):
         return obj.user.email
 
     def members(self, obj):
-        return self.render_all_sites_or_join(obj, 'member')
+        return self.get_sites_for_role(obj, 'member')
 
     def managers(self, obj):
-        return self.render_all_sites_or_join(obj, 'manager')
+        return self.get_sites_for_role(obj, 'manager')
 
     def editors(self, obj):
-        return self.render_all_sites_or_join(obj, 'editor')
+        return self.get_sites_for_role(obj, 'editor')
 
     def reviewers(self, obj):
-        return self.render_all_sites_or_join(obj, 'reviewer')
+        return self.get_sites_for_role(obj, 'reviewer')