diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index f91b791e68741a..a453de5d6d7d37 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -2615,13 +2615,13 @@ dummy_func(
             STAT_INC(FOR_ITER, hit);
             PyListObject *seq = it->it_seq;
             if (seq == NULL || it->it_index >= PyList_GET_SIZE(seq)) {
-                it->it_index = -1;
                 #ifndef Py_GIL_DISABLED
                 if (seq != NULL) {
                     it->it_seq = NULL;
                     Py_DECREF(seq);
                 }
                 #endif
+                it->it_index = -1;
                 Py_DECREF(iter);
                 STACK_SHRINK(1);
                 /* Jump forward oparg, then skip following END_FOR and POP_TOP instructions */
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 068eefafd1b4a4..c23c8bf99c8aff 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -2553,13 +2553,13 @@
                 STAT_INC(FOR_ITER, hit);
                 PyListObject *seq = it->it_seq;
                 if (seq == NULL || it->it_index >= PyList_GET_SIZE(seq)) {
-                    it->it_index = -1;
                     #ifndef Py_GIL_DISABLED
                     if (seq != NULL) {
                         it->it_seq = NULL;
                         Py_DECREF(seq);
                     }
                     #endif
+                    it->it_index = -1;
                     Py_DECREF(iter);
                     STACK_SHRINK(1);
                     /* Jump forward oparg, then skip following END_FOR and POP_TOP instructions */