diff --git a/dibi/drivers/postgre.php b/dibi/drivers/postgre.php
index 509e378e..51decb16 100644
--- a/dibi/drivers/postgre.php
+++ b/dibi/drivers/postgre.php
@@ -19,8 +19,8 @@
 class DibiPostgreDriver extends DibiDriver
 {
     public $formats = array(
-        'TRUE'     => "1",
-        'FALSE'    => "0",
+        'TRUE'     => "TRUE",
+        'FALSE'    => "FALSE",
         'date'     => "'Y-m-d'",
         'datetime' => "'Y-m-d H:i:s'",
     );
diff --git a/dibi/drivers/untested/mssql.php b/dibi/drivers/untested/mssql.php
index da86fbba..b00a7cea 100644
--- a/dibi/drivers/untested/mssql.php
+++ b/dibi/drivers/untested/mssql.php
@@ -19,7 +19,7 @@
 class DibiMsSqlDriver extends DibiDriver
 {
     public $formats = array(
-        'TRUE'     => "1",
+        'TRUE'     => "-1",
         'FALSE'    => "0",
         'date'     => "'Y-m-d'",
         'datetime' => "'Y-m-d H:i:s'",