diff --git a/src/kirin/dialects/ilist/rewrite/hint_len.py b/src/kirin/dialects/ilist/rewrite/hint_len.py
index b20229ec7..4c535474e 100644
--- a/src/kirin/dialects/ilist/rewrite/hint_len.py
+++ b/src/kirin/dialects/ilist/rewrite/hint_len.py
@@ -1,6 +1,6 @@
 from kirin import ir, types
 from kirin.analysis import const
-from kirin.dialects import py
+from kirin.dialects import py, scf
 from kirin.rewrite.abc import RewriteRule, RewriteResult
 from kirin.dialects.ilist.stmts import IListType
 
@@ -26,7 +26,11 @@ def _get_collection_len(self, collection: ir.SSAValue):
             return None
 
     def rewrite_Statement(self, node: ir.Statement) -> RewriteResult:
-        if not isinstance(node, py.Len):
+
+        if not (
+            isinstance(node, py.Len)
+            and not isinstance(node.parent_stmt, (scf.For, scf.IfElse))
+        ):
             return RewriteResult()
 
         if (coll_len := self._get_collection_len(node.value)) is None: