diff --git a/backend/Core/Weeks/Week.cs b/backend/Core/Weeks/Week.cs
index 46ed521d..e0d99c72 100644
--- a/backend/Core/Weeks/Week.cs
+++ b/backend/Core/Weeks/Week.cs
@@ -171,6 +171,9 @@ private bool DateIsInWeek(DateOnly day)
 
     public static bool operator ==(Week left, Week right)
     {
+        if (ReferenceEquals(left, right)) return true;
+        if (ReferenceEquals(left, null)) return false;
+        if (ReferenceEquals(right, null)) return false;
         return left.Year == right.Year && left.WeekNumber == right.WeekNumber;
     }