@@ -, +, @@ 
---
 api/v1/swagger/definitions/booking.yaml        | 8 ++++----
 installer/data/mysql/atomicupdate/bug_36120.pl | 9 +++++++++
 installer/data/mysql/kohastructure.sql         | 2 +-
 3 files changed, 14 insertions(+), 5 deletions(-)
--- a/api/v1/swagger/definitions/booking.yaml	
+++ a/api/v1/swagger/definitions/booking.yaml	
@@ -18,12 +18,12 @@ properties:
     description: Internal item identifier
     type:
       - integer
-      - "null"
+      - 'null'
   item:
     description: Embedable item representation
     type:
       - object
-      - "null"
+      - 'null'
   patron_id:
     description: Internal patron identifier
     type: integer
@@ -31,7 +31,7 @@ properties:
     description: Embedable patron representation
     type:
       - object
-      - "null"
+      - 'null'
   pickup_library_id:
     description: Internal pickup_library identifier
     type: string
@@ -39,7 +39,7 @@ properties:
     description: Embedable pickup_library representation
     type:
       - object
-      - "null"
+      - 'null'
   start_date:
     description: Start date and time of this booking
     format: date-time
--- a/installer/data/mysql/atomicupdate/bug_36120.pl	
+++ a/installer/data/mysql/atomicupdate/bug_36120.pl	
@@ -19,6 +19,15 @@ return {
           $dbh->do(
               q{UPDATE bookings JOIN items ON bookings.item_id = items.itemnumber SET bookings.pickup_library_id = items.homebranch }
           );
+
+          say $out "Set existing bookings pickup location to item homebranch";
+
+          $dbh->do(q{
+              ALTER TABLE bookings
+              MODIFY pickup_library_id varchar(10) NOT NULL COMMENT 'Identifier for booking pickup library'
+          });
+
+          say $out "Set pickup_library_id to NOT NULL";
         }
     },
 };
--- a/installer/data/mysql/kohastructure.sql	
+++ a/installer/data/mysql/kohastructure.sql	
@@ -1208,7 +1208,7 @@ CREATE TABLE `bookings` (
   `patron_id` int(11) NOT NULL DEFAULT 0 COMMENT 'foreign key from the borrowers table defining which patron this booking is for',
   `biblio_id` int(11) NOT NULL DEFAULT 0 COMMENT 'foreign key from the biblio table defining which bib record this booking is on',
   `item_id` int(11) DEFAULT NULL COMMENT 'foreign key from the items table defining the specific item the patron has placed a booking for',
-  `pickup_library_id` varchar(10) DEFAULT NULL COMMENT 'Identifier for booking pickup library',
+  `pickup_library_id` varchar(10) NOT NULL COMMENT 'Identifier for booking pickup library',
   `start_date` datetime DEFAULT NULL COMMENT 'the start date of the booking',
   `end_date` datetime DEFAULT NULL COMMENT 'the end date of the booking',
   PRIMARY KEY (`booking_id`),
--