diff --git a/device/device.go b/device/device.go
index 747a1360..d1acdcd3 100644
--- a/device/device.go
+++ b/device/device.go
@@ -7,19 +7,20 @@ import (
 
 	"github.com/micromdm/dep"
 	//"github.com/micromdm/mdm"
+	"database/sql"
 )
 
 // Device represents an iOS or OS X Computer
 type Device struct {
 	// Primary key is UUID
-	UUID         string `json:"uuid" db:"device_uuid"`
-	UDID         string `json:"udid,omitempty"`
-	SerialNumber string `json:"serial_number,omitempty" db:"serial_number,omitempty"`
-	OSVersion    string `json:"os_version,omitempty" db:"os_version,omitempty"`
-	BuildVersion string `json:"build_version,omitempty" db:"build_version,omitempty"`
-	ProductName  string `json:"product_name,omitempty" db:"product_name,omitempty"`
-	IMEI         string `json:"imei,omitempty" db:"imei,omitempty"`
-	MEID         string `json:"meid,omitempty" db:"meid,omitempty"`
+	UUID         string         `json:"uuid" db:"device_uuid"`
+	UDID         sql.NullString `json:"udid,omitempty"`
+	SerialNumber sql.NullString `json:"serial_number,omitempty" db:"serial_number,omitempty"`
+	OSVersion    string         `json:"os_version,omitempty" db:"os_version,omitempty"`
+	BuildVersion string         `json:"build_version,omitempty" db:"build_version,omitempty"`
+	ProductName  string         `json:"product_name,omitempty" db:"product_name,omitempty"`
+	IMEI         string         `json:"imei,omitempty" db:"imei,omitempty"`
+	MEID         string         `json:"meid,omitempty" db:"meid,omitempty"`
 	//Apple MDM Protocol Topic
 	MDMTopic               string           `json:"mdm_topic,omitempty" db:"apple_mdm_topic,omitempty"`
 	PushMagic              string           `json:"push_magic,omitempty" db:"apple_push_magic,omitempty"`
diff --git a/migrations/201606280001_devices_idx_uuid_sn_down.sql b/migrations/201606280001_devices_idx_uuid_sn_down.sql
index 2ca9de23..69864ca1 100644
--- a/migrations/201606280001_devices_idx_uuid_sn_down.sql
+++ b/migrations/201606280001_devices_idx_uuid_sn_down.sql
@@ -1,4 +1,10 @@
 DROP INDEX IF EXISTS serial_idx;
 DROP INDEX IF EXISTS udid_idx;
 
+UPDATE devices SET udid = '' WHERE udid IS NULL;
+UPDATE devices SET serial_number = '' WHERE serial_number IS NULL;
+
+ALTER TABLE devices
+  ALTER COLUMN udid SET NOT NULL;
+
 CREATE UNIQUE INDEX IF NOT EXISTS udid_serial_idx ON devices (udid, serial_number);
\ No newline at end of file
diff --git a/migrations/201606280001_devices_idx_uuid_sn_up.sql b/migrations/201606280001_devices_idx_uuid_sn_up.sql
index 84f58f9c..93c77a68 100644
--- a/migrations/201606280001_devices_idx_uuid_sn_up.sql
+++ b/migrations/201606280001_devices_idx_uuid_sn_up.sql
@@ -1,5 +1,11 @@
 -- Add the UUID and Serial Number back as individual UNIQUE constraints, along with others
 DROP INDEX udid_serial_idx;
 
+ALTER TABLE devices
+    ALTER COLUMN udid DROP NOT NULL;
+
+UPDATE devices SET udid = NULL WHERE udid = '';
+UPDATE devices SET serial_number = NULL WHERE serial_number = '';
+
 CREATE UNIQUE INDEX IF NOT EXISTS serial_idx ON devices (serial_number);
 CREATE UNIQUE INDEX IF NOT EXISTS udid_idx ON devices (udid);