diff --git a/airtime_mvc/application/configs/constants.php b/airtime_mvc/application/configs/constants.php
index 4360cd9e7..aaed5d901 100644
--- a/airtime_mvc/application/configs/constants.php
+++ b/airtime_mvc/application/configs/constants.php
@@ -24,7 +24,8 @@ define('LICENSE_URL'        , 'http://www.gnu.org/licenses/agpl-3.0-standalone.h
 define('AIRTIME_COPYRIGHT_DATE' , '2010-2015');
 define('AIRTIME_REST_VERSION'   , '1.1');
 define('AIRTIME_API_VERSION'    , '1.1');
-define('AIRTIME_CODE_VERSION'   , '2.5.13');
+// XXX: it's important that we upgrade this every time we add an upgrade!
+define('AIRTIME_CODE_VERSION'   , '2.5.14');
 
 // Defaults
 define('DEFAULT_LOGO_PLACEHOLDER', 1);
diff --git a/airtime_mvc/application/controllers/upgrade_sql/airtime_2.5.14/upgrade.sql b/airtime_mvc/application/controllers/upgrade_sql/airtime_2.5.14/upgrade.sql
new file mode 100644
index 000000000..3a5362ca1
--- /dev/null
+++ b/airtime_mvc/application/controllers/upgrade_sql/airtime_2.5.14/upgrade.sql
@@ -0,0 +1,4 @@
+ALTER TABLE cc_pref ALTER COLUMN subjid SET NULL;
+ALTER TABLE cc_pref ALTER COLUMN subjid SET DEFAULT NULL;
+CREATE UNIQUE INDEX cc_pref_key_idx ON cc_pref (keystr) WHERE subjid IS NULL;
+ANALYZE cc_pref;
\ No newline at end of file
diff --git a/airtime_mvc/application/models/Preference.php b/airtime_mvc/application/models/Preference.php
index ec8b49a3c..736dbef98 100644
--- a/airtime_mvc/application/models/Preference.php
+++ b/airtime_mvc/application/models/Preference.php
@@ -31,7 +31,8 @@ class Application_Model_Preference
         $con->beginTransaction();
 
         try {
-            static::_lock($con);
+            /* Comment this out while we reevaluate it in favor of a unique constraint
+            static::_lock($con); */
             $userId = self::getUserId();
             
             if ($isUserValue && is_null($userId)) {
diff --git a/airtime_mvc/application/upgrade/Upgrades.php b/airtime_mvc/application/upgrade/Upgrades.php
index aa012eca6..bcd9c5093 100644
--- a/airtime_mvc/application/upgrade/Upgrades.php
+++ b/airtime_mvc/application/upgrade/Upgrades.php
@@ -455,3 +455,21 @@ class AirtimeUpgrader2513 extends AirtimeUpgrader
         return '2.5.13';
     }
 }
+
+/**
+ * Class AirtimeUpgrader2514
+ *
+ * SAAS-923 - Add a partial constraint to cc_pref so that keystrings must be unique
+ */
+class AirtimeUpgrader2514 extends AirtimeUpgrader
+{
+    protected function getSupportedSchemaVersions() {
+        return array (
+            '2.5.13'
+        );
+    }
+
+    public function getNewVersion() {
+        return '2.5.14';
+    }
+}
diff --git a/airtime_mvc/build/sql/defaultdata.sql b/airtime_mvc/build/sql/defaultdata.sql
index 49bf3ff29..30fd8d765 100644
--- a/airtime_mvc/build/sql/defaultdata.sql
+++ b/airtime_mvc/build/sql/defaultdata.sql
@@ -376,3 +376,11 @@ INSERT INTO cc_stream_setting ("keyname", "value", "type") VALUES ('s4_descripti
 INSERT INTO cc_stream_setting ("keyname", "value", "type") VALUES ('s4_genre', '', 'string');
 INSERT INTO cc_stream_setting (keyname, value, type) VALUES ('s4_channels', 'stereo', 'string');
 
+-- added in 2.5.14 - this can't be set up in Propel's XML schema, so we need to do it here -- Duncan
+
+ALTER TABLE cc_pref ALTER COLUMN subjid SET NULL;
+ALTER TABLE cc_pref ALTER COLUMN subjid SET DEFAULT NULL;
+CREATE UNIQUE INDEX cc_pref_key_idx ON cc_pref (keystr) WHERE subjid IS NULL;
+ANALYZE cc_pref; -- this validates the new partial index
+
+--end added in 2.5.14