diff --git a/src/Bosnadev/Database/Schema/Grammars/PostgresGrammar.php b/src/Bosnadev/Database/Schema/Grammars/PostgresGrammar.php
index fb13fcc..0bb9525 100644
--- a/src/Bosnadev/Database/Schema/Grammars/PostgresGrammar.php
+++ b/src/Bosnadev/Database/Schema/Grammars/PostgresGrammar.php
@@ -2,6 +2,7 @@
 
 namespace Bosnadev\Database\Schema\Grammars;
 
+use Illuminate\Contracts\Database\Query\Expression;
 use Illuminate\Support\Fluent;
 use Illuminate\Database\Schema\Blueprint as BaseBlueprint;
 use Bosnadev\Database\Schema\Blueprint;
@@ -284,7 +285,7 @@ protected function typeTsvector(Fluent $column)
      */
     protected function getDefaultValue($value)
     {
-        if($this->isUuid($value)) return strval($value);
+        if($this->isUuid($value)) return $value instanceof Expression ? $this->getValue($value) : strval($value);
 
         return parent::getDefaultValue($value);
     }
@@ -297,6 +298,10 @@ protected function getDefaultValue($value)
      */
     protected function isUuid($value)
     {
+        if ($value instanceof Expression) {
+            $value = $this->getValue($value);
+        }
+
         return preg_match('/^uuid_generate_v/', $value);
     }