diff --git a/pymbolic/mapper/__init__.py b/pymbolic/mapper/__init__.py
index 396dcd2973e0355c4e8b6f7e66f8df5fcffdb103..0a337710b7a54f37a770b8a693c66d7736f29d55 100644
--- a/pymbolic/mapper/__init__.py
+++ b/pymbolic/mapper/__init__.py
@@ -71,14 +71,14 @@ class Mapper(object):
 
 
 class RecursiveMapper(Mapper):
-    def rec(self, expr, *args):
+    def rec(self, expr, *args, **kwargs):
         try:
             method = expr.get_mapper_method(self)
         except AttributeError:
             if isinstance(expr, primitives.Expression):
-                return self.handle_unsupported_expression(expr, *args)
+                return self.handle_unsupported_expression(expr, *args, **kwargs)
             else:
-                return self.map_foreign(expr, *args)
+                return self.map_foreign(expr, *args, **kwargs)
         else:
             return method(expr, *args)