diff --git a/Koha/Biblio.pm b/Koha/Biblio.pm
index d6a46fb185..23841897bc 100644
--- a/Koha/Biblio.pm
+++ b/Koha/Biblio.pm
@@ -1706,7 +1706,12 @@ sub to_api {
     $args = defined $args ? {%$args} : {};
     delete $args->{embed};
 
-    my $json_biblioitem = $self->biblioitem->to_api( $args );
+    my $biblioitem = $self->biblioitem;
+
+    Koha::Exceptions::RelatedObjectNotFound->throw( accessor => 'biblioitem', class => 'Koha::Biblioitem' )
+        unless $biblioitem;
+
+    my $json_biblioitem = $biblioitem->to_api($args);
     return unless $json_biblioitem;
 
     return { %$json_biblioitem, %$json_biblio };
diff --git a/Koha/Exceptions.pm b/Koha/Exceptions.pm
index 0d5a1ac1ed..d308f19229 100644
--- a/Koha/Exceptions.pm
+++ b/Koha/Exceptions.pm
@@ -7,16 +7,16 @@ use Koha::Exception;
 use Exception::Class (
 
     'Koha::Exceptions::BadParameter' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'A bad parameter was given',
-        fields => ['parameter'],
+        fields      => ['parameter'],
     },
     'Koha::Exceptions::DuplicateObject' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'Same object already exists',
     },
     'Koha::Exceptions::FileNotFound' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'File not found',
         fields      => ['filename'],
     },
@@ -26,57 +26,62 @@ use Exception::Class (
         fields      => ['invalid_status'],
     },
     'Koha::Exceptions::ObjectNotFound' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'The required object doesn\'t exist',
     },
     'Koha::Exceptions::PayloadTooLarge' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'Request entity is larger than limits defined by server',
     },
     'Koha::Exceptions::ObjectNotCreated' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'The object have not been created',
     },
+    'Koha::Exceptions::RelatedObjectNotFound' => {
+        isa         => 'Koha::Exception',
+        description => 'The requested related object does not exist',
+        fields      => [ 'accessor', 'class' ],
+    },
     'Koha::Exceptions::CannotDeleteDefault' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'The default value cannot be deleted'
     },
     'Koha::Exceptions::CannotDeleteSystem' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'The system value cannot be deleted'
     },
     'Koha::Exceptions::MissingParameter' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'A required parameter is missing',
-        fields => ['parameter'],
+        fields      => ['parameter'],
     },
     'Koha::Exceptions::TooManyParameters' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'Too many parameters given',
     },
     'Koha::Exceptions::ParameterTooHigh' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'A passed parameter value is too high'
     },
     'Koha::Exceptions::NoChanges' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'No changes were made',
     },
     'Koha::Exceptions::WrongParameter' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'Parameter has wrong value or type',
-        fields => ['name', 'value', 'type'],
+        fields      => [ 'name', 'value', 'type' ],
     },
     'Koha::Exceptions::NoPermission' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'You do not have permission for this action',
     },
     'Koha::Exceptions::CannotAddLibraryLimit' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'General problem adding a library limit'
     },
     'Koha::Exceptions::UnderMaintenance' => {
-        isa => 'Koha::Exception',
+        isa         => 'Koha::Exception',
         description => 'Koha is under maintenance.'
     },
     'Koha::Exceptions::NoInteger' => {