diff --git a/loopy/symbolic.py b/loopy/symbolic.py
index b0c621539aa008cd6c72d7431883716b7c993d74..054ed878171bd815676cc0ff45617b156f6f06e5 100644
--- a/loopy/symbolic.py
+++ b/loopy/symbolic.py
@@ -73,8 +73,8 @@ class SubstitutionMapper(SubstitutionMapperBase, IdentityMapperMixin):
 
 class StringifyMapper(StringifyMapperBase):
     def map_reduction(self, expr, prec):
-        return "reduce(%s, [%s], %s, tag=%s)" % (
-                expr.operation, ", ".join(expr.inames), expr.expr, expr.tag)
+        return "reduce(%s, [%s], %s)" % (
+                expr.operation, ", ".join(expr.inames), expr.expr)
 
 class DependencyMapper(DependencyMapperBase):
     def map_reduction(self, expr):