diff --git a/VERSION b/VERSION
index 4bc3af01..d27fe888 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-Version 2.4.1-alpha.2+timestamp.2013.02.14.17.33.32
+Version 2.4.1-alpha.2+timestamp.2013.02.15.10.50.49
diff --git a/gluon/validators.py b/gluon/validators.py
index f5942167..7cdd0649 100644
--- a/gluon/validators.py
+++ b/gluon/validators.py
@@ -237,6 +237,9 @@ class IS_EXPR(Validator):
         self.environment = environment or {}
 
     def __call__(self, value):
+        if callable(self.expression):
+            return (value, self.expression(value))
+        # for backward compatibility
         self.environment.update(value=value)
         exec '__ret__=' + self.expression in self.environment
         if self.environment['__ret__']: