diff --git a/lib/validator/sfValidatorSchema.class.php b/lib/validator/sfValidatorSchema.class.php
index 124e553f00..02e619d8e1 100644
--- a/lib/validator/sfValidatorSchema.class.php
+++ b/lib/validator/sfValidatorSchema.class.php
@@ -375,17 +375,18 @@ public function __clone()
   protected function getBytes($value)
   {
     $value = trim($value);
+    $size = (int) $value;
     switch (strtolower($value[strlen($value) - 1]))
     {
       // The 'G' modifier is available since PHP 5.1.0
       case 'g':
-        $value *= 1024;
+        $size *= 1024;
       case 'm':
-        $value *= 1024;
+        $size *= 1024;
       case 'k':
-        $value *= 1024;
+        $size *= 1024;
     }
 
-    return $value;
+    return $size;
   }
 }