diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tt
index e430f5e45b..dde1efaf4d 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tt
@@ -217,6 +217,9 @@ legend.collapsed i.fa.fa-caret-down::before {
                                     [% IF ( ERROR_cannot_delete_guarantor ) %]
                                         <li id="ERROR_cannot_delete_guarantor">Cannot delete guarantor(s). A child patron needs a guarantor.</li>
                                     [% END %]
+                                    [% IF ( ERROR_invalid_relationship ) %]
+                                        <li id="ERROR_invalid_relationship">Guarantor relationship is invalid.</li>
+                                    [% END %]
                                 </ul>
                             </div>
                         [% END %]
@@ -554,7 +557,7 @@ legend.collapsed i.fa.fa-caret-down::before {
                                                                             [% END %]
                                                                         [% END %]
                                                                     </select>
-                                                                    [% UNLESS mandatoryrelationship %]
+                                                                    [% IF mandatoryrelationship %]
                                                                         <span class="required">Required</span>
                                                                     [% END %]
                                                                 </li>
diff --git a/members/memberentry.pl b/members/memberentry.pl
index 3e75eeebde..7ee45c5eed 100755
--- a/members/memberentry.pl
+++ b/members/memberentry.pl
@@ -289,6 +289,22 @@ foreach my $guarantor (@guarantors) {
     }
 }
 
+my @valid_relationships = split(/\|/, C4::Context->preference('borrowerRelationship'), -1);
+if (@valid_relationships) {
+    my @new_guarantor_id           = $input->multi_param('new_guarantor_id');
+    my @new_guarantor_relationship = $input->multi_param('new_guarantor_relationship');
+
+    for ( my $i = 0 ; $i < scalar @new_guarantor_id; $i++ ) {
+        my $guarantor_id = $new_guarantor_id[$i];
+        my $relationship = $new_guarantor_relationship[$i];
+
+        next unless $guarantor_id;
+        unless ( grep { $_ eq $relationship } @valid_relationships ) {
+            push @errors, 'ERROR_invalid_relationship';
+        }
+    }
+}
+
 ###############test to take the right zipcode, country and city name ##############
 # set only if parameter was passed from the form
 $newdata{'city'}    = $input->param('city')    if defined($input->param('city'));