diff --git a/physics/admin.py b/physics/admin.py
index e719b760..9725fda9 100644
--- a/physics/admin.py
+++ b/physics/admin.py
@@ -24,7 +24,7 @@ class QuestionAdmin(VersionAdmin):
     #)
 
 class CidUserInline(admin.TabularInline):
-    model = CidUser
+    model = Exam.valid_users.through
     extra = 1
 
 class ExamAdmin(VersionAdmin, admin.ModelAdmin):