diff --git a/geneit_backend/src/controllers/members_controller.rs b/geneit_backend/src/controllers/members_controller.rs
index dafab9f..3651eff 100644
--- a/geneit_backend/src/controllers/members_controller.rs
+++ b/geneit_backend/src/controllers/members_controller.rs
@@ -82,6 +82,8 @@ enum MemberControllerErr {
     MotherNotExisting,
     #[error("Father does not exists!")]
     FatherNotExisting,
+    #[error("Mother and father can not be identical!")]
+    MotherAndFatherIdentical,
 }
 
 fn check_opt_str_val(
@@ -188,6 +190,10 @@ impl MemberRequest {
             if !members_service::exists(member.family_id(), mother).await? {
                 return Err(MemberControllerErr::MotherNotExisting.into());
             }
+
+            if self.mother == self.father {
+                return Err(MemberControllerErr::MotherAndFatherIdentical.into());
+            }
         }
 
         if let Some(father) = self.father {