diff --git a/storage/tracking.lisp b/storage/tracking.lisp
index 31295ca..fef4f51 100644
--- a/storage/tracking.lisp
+++ b/storage/tracking.lisp
@@ -18,11 +18,16 @@
    (container :initarg :container)))
 
 (defclass container ()
-  ((storage :initarg :storage)))
+  ((storage :initarg :storage)
+   (table-name :reader table-name :initform :tracks)
+   (head-fields :reader head-fields :initform '(:taskid :username))
+   (indexes :reader indexes :initform '((:taskid :username) (username)))))
 
-(defun create-table (st table-name head-fields) 
+(defun create-table (st cont) 
   (let*
-    ((params (storage:db-params st))
+    ((table-name (table-name cont))
+     (head-fields (head-fields cont))
+     (params (storage:db-params st))
      (id-type (getf params :id-type))
      (json-type (getf params :json-type))
      (hf-def (mapcar #'(lambda (x) 
@@ -34,7 +39,7 @@
           `((trackid :type ,id-type :primary-key t :not-null t))
           hf-def
           `((timestamp :type timestamptz :not-null t :default current_timestamp)
-            (data :type ,json-type)))))))
+            (data :type ,json-type :not-null t :default |'{}'|)))))))
 
 (defun create-indexes (st tname ixs)
   (let ((i 1)
diff --git a/test/test-storage.lisp b/test/test-storage.lisp
index c3386e5..b01ff3d 100644
--- a/test/test-storage.lisp
+++ b/test/test-storage.lisp
@@ -37,8 +37,9 @@
     (t:show-result)))
 
 (defun test-track (st)
-  (let ((tr (make-instance 'tracking:track)))
+  (let* ((cont (make-instance 'tracking:container))
+         (tr (make-instance 'tracking:track :container cont)))
     (storage:drop-table st :tracks)
-    (tracking:create-table st :tracks '(taskid username))
+    (tracking:create-table st cont)
     (tracking:create-indexes st :tracks '((taskid) (taskid username)))
     (== (tracking:data tr) nil)))