diff --git a/Misc/NEWS.d/next/C API/2020-11-18-09-46-35.bpo-1635741.SH8OIT.rst b/Misc/NEWS.d/next/C API/2020-11-18-09-46-35.bpo-1635741.SH8OIT.rst
new file mode 100644
index 0000000..34802cd
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2020-11-18-09-46-35.bpo-1635741.SH8OIT.rst
@@ -0,0 +1,2 @@
+Port :mod:`grp` and :mod:`pwd` extension modules to multiphase
+initialization (:pep:`489`)
diff --git a/Modules/grpmodule.c b/Modules/grpmodule.c
index c4d1681..f6298ca 100644
--- a/Modules/grpmodule.c
+++ b/Modules/grpmodule.c
@@ -46,20 +46,19 @@ get_grp_state(PyObject *module)
     return (grpmodulestate *)state;
 }
 
-#define modulestate_global get_grp_state(PyState_FindModule(&grpmodule))
-
 static struct PyModuleDef grpmodule;
 
 #define DEFAULT_BUFFER_SIZE 1024
 
 static PyObject *
-mkgrent(struct group *p)
+mkgrent(PyObject *module, struct group *p)
 {
     int setIndex = 0;
     PyObject *v, *w;
     char **member;
 
-    if ((v = PyStructSequence_New(modulestate_global->StructGrpType)) == NULL)
+    v = PyStructSequence_New(get_grp_state(module)->StructGrpType);
+    if (v == NULL)
         return NULL;
 
     if ((w = PyList_New(0)) == NULL) {
@@ -170,7 +169,7 @@ grp_getgrgid_impl(PyObject *module, PyObject *id)
         Py_DECREF(gid_obj);
         return NULL;
     }
-    retval = mkgrent(p);
+    retval = mkgrent(module, p);
 #ifdef HAVE_GETGRGID_R
     PyMem_RawFree(buf);
 #endif
@@ -248,7 +247,7 @@ grp_getgrnam_impl(PyObject *module, PyObject *name)
         }
         goto out;
     }
-    retval = mkgrent(p);
+    retval = mkgrent(module, p);
 out:
     PyMem_RawFree(buf);
     Py_DECREF(bytes);
@@ -275,7 +274,7 @@ grp_getgrall_impl(PyObject *module)
         return NULL;
     setgrent();
     while ((p = getgrent()) != NULL) {
-        PyObject *v = mkgrent(p);
+        PyObject *v = mkgrent(module, p);
         if (v == NULL || PyList_Append(d, v) != 0) {
             Py_XDECREF(v);
             Py_DECREF(d);
@@ -311,6 +310,26 @@ users are not explicitly listed as members of the groups they are in\n\
 according to the password database.  Check both databases to get\n\
 complete membership information.)");
 
+static int
+grpmodule_exec(PyObject *module)
+{
+    grpmodulestate *state = get_grp_state(module);
+
+    state->StructGrpType = PyStructSequence_NewType(&struct_group_type_desc);
+    if (state->StructGrpType == NULL) {
+        return -1;
+    }
+    if (PyModule_AddType(module, state->StructGrpType) < 0) {
+        return -1;
+    }
+    return 0;
+}
+
+static PyModuleDef_Slot grpmodule_slots[] = {
+    {Py_mod_exec, grpmodule_exec},
+    {0, NULL}
+};
+
 static int grpmodule_traverse(PyObject *m, visitproc visit, void *arg) {
     Py_VISIT(get_grp_state(m)->StructGrpType);
     return 0;
@@ -326,37 +345,19 @@ static void grpmodule_free(void *m) {
 }
 
 static struct PyModuleDef grpmodule = {
-        PyModuleDef_HEAD_INIT,
-        "grp",
-        grp__doc__,
-        sizeof(grpmodulestate),
-        grp_methods,
-        NULL,
-        grpmodule_traverse,
-        grpmodule_clear,
-        grpmodule_free,
+    PyModuleDef_HEAD_INIT,
+    .m_name = "grp",
+    .m_doc = grp__doc__,
+    .m_size = sizeof(grpmodulestate),
+    .m_methods = grp_methods,
+    .m_slots = grpmodule_slots,
+    .m_traverse = grpmodule_traverse,
+    .m_clear = grpmodule_clear,
+    .m_free = grpmodule_free,
 };
 
 PyMODINIT_FUNC
 PyInit_grp(void)
 {
-    PyObject *m;
-    if ((m = PyState_FindModule(&grpmodule)) != NULL) {
-        Py_INCREF(m);
-        return m;
-    }
-
-    if ((m = PyModule_Create(&grpmodule)) == NULL) {
-        return NULL;
-    }
-
-    grpmodulestate *state = PyModule_GetState(m);
-    state->StructGrpType = PyStructSequence_NewType(&struct_group_type_desc);
-    if (state->StructGrpType == NULL) {
-        return NULL;
-    }
-
-    Py_INCREF(state->StructGrpType);
-    PyModule_AddObject(m, "struct_group", (PyObject *) state->StructGrpType);
-    return m;
+   return PyModuleDef_Init(&grpmodule);
 }
diff --git a/Modules/pwdmodule.c b/Modules/pwdmodule.c
index 901a3ed..14d3f9d 100644
--- a/Modules/pwdmodule.c
+++ b/Modules/pwdmodule.c
@@ -59,8 +59,6 @@ get_pwd_state(PyObject *module)
     return (pwdmodulestate *)state;
 }
 
-#define modulestate_global get_pwd_state(PyState_FindModule(&pwdmodule))
-
 static struct PyModuleDef pwdmodule;
 
 #define DEFAULT_BUFFER_SIZE 1024
@@ -79,10 +77,10 @@ sets(PyObject *v, int i, const char* val)
 }
 
 static PyObject *
-mkpwent(struct passwd *p)
+mkpwent(PyObject *module, struct passwd *p)
 {
     int setIndex = 0;
-    PyObject *v = PyStructSequence_New(modulestate_global->StructPwdType);
+    PyObject *v = PyStructSequence_New(get_pwd_state(module)->StructPwdType);
     if (v == NULL)
         return NULL;
 
@@ -194,7 +192,7 @@ pwd_getpwuid(PyObject *module, PyObject *uidobj)
         Py_DECREF(uid_obj);
         return NULL;
     }
-    retval = mkpwent(p);
+    retval = mkpwent(module, p);
 #ifdef HAVE_GETPWUID_R
     PyMem_RawFree(buf);
 #endif
@@ -274,7 +272,7 @@ pwd_getpwnam_impl(PyObject *module, PyObject *name)
         }
         goto out;
     }
-    retval = mkpwent(p);
+    retval = mkpwent(module, p);
 out:
     PyMem_RawFree(buf);
     Py_DECREF(bytes);
@@ -300,7 +298,7 @@ pwd_getpwall_impl(PyObject *module)
         return NULL;
     setpwent();
     while ((p = getpwent()) != NULL) {
-        PyObject *v = mkpwent(p);
+        PyObject *v = mkpwent(module, p);
         if (v == NULL || PyList_Append(d, v) != 0) {
             Py_XDECREF(v);
             Py_DECREF(d);
@@ -323,6 +321,26 @@ static PyMethodDef pwd_methods[] = {
     {NULL,              NULL}           /* sentinel */
 };
 
+static int
+pwdmodule_exec(PyObject *module)
+{
+    pwdmodulestate *state = get_pwd_state(module);
+
+    state->StructPwdType = PyStructSequence_NewType(&struct_pwd_type_desc);
+    if (state->StructPwdType == NULL) {
+        return -1;
+    }
+    if (PyModule_AddType(module, state->StructPwdType) < 0) {
+        return -1;
+    }
+    return 0;
+}
+
+static PyModuleDef_Slot pwdmodule_slots[] = {
+    {Py_mod_exec, pwdmodule_exec},
+    {0, NULL}
+};
+
 static int pwdmodule_traverse(PyObject *m, visitproc visit, void *arg) {
     Py_VISIT(get_pwd_state(m)->StructPwdType);
     return 0;
@@ -337,34 +355,19 @@ static void pwdmodule_free(void *m) {
 
 static struct PyModuleDef pwdmodule = {
     PyModuleDef_HEAD_INIT,
-    "pwd",
-    pwd__doc__,
-    sizeof(pwdmodulestate),
-    pwd_methods,
-    NULL,
-    pwdmodule_traverse,
-    pwdmodule_clear,
-    pwdmodule_free,
+    .m_name = "pwd",
+    .m_doc = pwd__doc__,
+    .m_size = sizeof(pwdmodulestate),
+    .m_methods = pwd_methods,
+    .m_slots = pwdmodule_slots,
+    .m_traverse = pwdmodule_traverse,
+    .m_clear = pwdmodule_clear,
+    .m_free = pwdmodule_free,
 };
 
 
 PyMODINIT_FUNC
 PyInit_pwd(void)
 {
-    PyObject *m;
-    if ((m = PyState_FindModule(&pwdmodule)) != NULL) {
-        Py_INCREF(m);
-        return m;
-    }
-    if ((m = PyModule_Create(&pwdmodule)) == NULL)
-        return NULL;
-
-    pwdmodulestate *state = PyModule_GetState(m);
-    state->StructPwdType = PyStructSequence_NewType(&struct_pwd_type_desc);
-    if (state->StructPwdType == NULL) {
-        return NULL;
-    }
-    Py_INCREF(state->StructPwdType);
-    PyModule_AddObject(m, "struct_passwd", (PyObject *) state->StructPwdType);
-    return m;
+    return PyModuleDef_Init(&pwdmodule);
 }