diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-04-11-13-07-49.bpo-4022.Ctpn_F.rst b/Misc/NEWS.d/next/Core and Builtins/2020-04-11-13-07-49.bpo-4022.Ctpn_F.rst
new file mode 100644
index 0000000..a13a8e8
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2020-04-11-13-07-49.bpo-4022.Ctpn_F.rst
@@ -0,0 +1 @@
+Improve performance of generators by not raising internal StopIteration.
diff --git a/Objects/genobject.c b/Objects/genobject.c
index 09efbab..1393f42 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -231,7 +231,8 @@
             if (PyAsyncGen_CheckExact(gen)) {
                 PyErr_SetNone(PyExc_StopAsyncIteration);
             }
-            else {
+            else if (arg) {
+                /* Set exception if not called by gen_iternext() */
                 PyErr_SetNone(PyExc_StopIteration);
             }
         }