diff --git a/flake8_simplify/rules/ast_for.py b/flake8_simplify/rules/ast_for.py
index 8d4d984..e19f64c 100644
--- a/flake8_simplify/rules/ast_for.py
+++ b/flake8_simplify/rules/ast_for.py
@@ -48,7 +48,15 @@ def get_sim104(node: ast.For) -> List[Tuple[int, int, str]]:
         or node.orelse != []
     ):
         return errors
-    if isinstance(node.parent, ast.AsyncFunctionDef):  # type: ignore
+
+    parent = getattr(node, "parent", None)
+    while (parent
+           and hasattr(parent, "parent")
+           and parent.parent is not parent
+           and not isinstance(parent, ast.AsyncFunctionDef)):
+        parent = getattr(parent, "parent", None)
+
+    if isinstance(parent, ast.AsyncFunctionDef):  # type: ignore
         return errors
     iterable = to_source(node.iter)
     errors.append(
diff --git a/tests/test_100_rules.py b/tests/test_100_rules.py
index fba08fe..955d71d 100644
--- a/tests/test_100_rules.py
+++ b/tests/test_100_rules.py
@@ -99,6 +99,17 @@ def test_s104_async_generator_false_positive():
         assert "SIM104" not in el
 
 
+def test_s104_async_generator_false_positive_2():
+    ret = _results(
+        """async def items():
+    with open('/etc/passwd') as f:
+        for line in f:
+            yield line"""
+    )
+    for el in ret:
+        assert "SIM104" not in el
+
+
 def test_sim105():
     ret = _results(
         """try: