diff --git a/Include/internal/pycore_genobject.h b/Include/internal/pycore_genobject.h
index f6d7e6d367177b..359253efc7a028 100644
--- a/Include/internal/pycore_genobject.h
+++ b/Include/internal/pycore_genobject.h
@@ -13,7 +13,7 @@ extern "C" {
 /* _PyGenObject_HEAD defines the initial segment of generator
    and coroutine objects. */
 #define _PyGenObject_HEAD(prefix)                                           \
-    PyObject_HEAD                                                           \
+    PyObject_VAR_HEAD                                                       \
     /* List of weak reference. */                                           \
     PyObject *prefix##_weakreflist;                                         \
     /* Name of the generator. */                                            \
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index d839893d2c657e..7328f4eadef37c 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -1641,7 +1641,7 @@ def bar(cls):
             check(bar, size('PP'))
         # generator
         def get_gen(): yield 1
-        check(get_gen(), size('6P4c' + INTERPRETER_FRAME + 'P'))
+        check(get_gen(), size('7P4c' + INTERPRETER_FRAME + 'P'))
         # iterator
         check(iter('abc'), size('lP'))
         # callable-iterator