diff --git a/src/calibre/library/sqlite_custom.c b/src/calibre/library/sqlite_custom.c
index 114374103b..9ed40a2b61 100644
--- a/src/calibre/library/sqlite_custom.c
+++ b/src/calibre/library/sqlite_custom.c
@@ -273,22 +273,17 @@ static PyMethodDef sqlite_custom_methods[] = {
     {NULL, NULL, 0, NULL}
 };
 
-static struct PyModuleDef sqlite_custom_module = {
-    /* m_base     */ PyModuleDef_HEAD_INIT,
-    /* m_name     */ "sqlite_custom",
-    /* m_doc      */ sqlite_custom_doc,
-    /* m_size     */ -1,
-    /* m_methods  */ sqlite_custom_methods,
-    /* m_slots    */ 0,
-    /* m_traverse */ 0,
-    /* m_clear    */ 0,
-    /* m_free     */ 0,
+static int
+exec_module(PyObject *module) { return 0; }
+
+static PyModuleDef_Slot slots[] = { {Py_mod_exec, exec_module}, {0, NULL} };
+
+static struct PyModuleDef module_def = {
+    .m_base     = PyModuleDef_HEAD_INIT,
+    .m_name     = "sqlite_custom",
+    .m_doc      = sqlite_custom_doc,
+    .m_methods  = sqlite_custom_methods,
+    .m_slots    = slots,
 };
-CALIBRE_MODINIT_FUNC PyInit_sqlite_custom(void) {
-    PyObject *m;
-    m = PyModule_Create(&sqlite_custom_module);
-    if (m == NULL) {
-        return NULL;
-    }
-    return m;
-}
+
+CALIBRE_MODINIT_FUNC PyInit_sqlite_custom(void) { return PyModuleDef_Init(&module_def); }
diff --git a/src/calibre/utils/fonts/freetype.cpp b/src/calibre/utils/fonts/freetype.cpp
index 7c8eca408a..afaa65371f 100644
--- a/src/calibre/utils/fonts/freetype.cpp
+++ b/src/calibre/utils/fonts/freetype.cpp
@@ -288,47 +288,34 @@ static PyTypeObject FreeTypeType = { // {{{
 
 static char freetype_doc[] = "Interface to freetype";
 
-static PyMethodDef freetype_methods[] = {
-    {NULL, NULL, 0, NULL}
-};
-
-static struct PyModuleDef freetype_module = {
-    /* m_base     */ PyModuleDef_HEAD_INIT,
-    /* m_name     */ "freetype",
-    /* m_doc      */ freetype_doc,
-    /* m_size     */ -1,
-    /* m_methods  */ freetype_methods,
-    /* m_slots    */ 0,
-    /* m_traverse */ 0,
-    /* m_clear    */ 0,
-    /* m_free     */ 0,
-};
-CALIBRE_MODINIT_FUNC PyInit_freetype(void) {
-    PyObject *m;
-
+static int
+exec_module(PyObject *m) {
     FreeTypeType.tp_new = PyType_GenericNew;
-    if (PyType_Ready(&FreeTypeType) < 0) {
-        return NULL;
-    }
+    if (PyType_Ready(&FreeTypeType) < 0) return -1;
 
     FaceType.tp_new = PyType_GenericNew;
-    if (PyType_Ready(&FaceType) < 0) {
-        return NULL;
-    }
-
-    m = PyModule_Create(&freetype_module);
-    if (m == NULL) {
-        return NULL;
-    }
+    if (PyType_Ready(&FaceType) < 0) return -1;
 
     FreeTypeError = PyErr_NewException((char*)"freetype.FreeTypeError", NULL, NULL);
-    if (FreeTypeError == NULL) {
-        return NULL;
-    }
+    if (FreeTypeError == NULL) return -1;
     PyModule_AddObject(m, "FreeTypeError", FreeTypeError);
 
     Py_INCREF(&FreeTypeType);
     PyModule_AddObject(m, "FreeType", (PyObject *)&FreeTypeType);
+    Py_INCREF(&FaceType);
     PyModule_AddObject(m, "Face", (PyObject *)&FaceType);
-    return m;
+	return 0;
+}
+
+static PyModuleDef_Slot slots[] = { {Py_mod_exec, (void*)exec_module}, {0, NULL} };
+
+static struct PyModuleDef module_def = {0};
+
+CALIBRE_MODINIT_FUNC PyInit_freetype(void) {
+
+	module_def.m_base = PyModuleDef_HEAD_INIT;
+	module_def.m_name = "freetype";
+	module_def.m_doc = freetype_doc;
+	module_def.m_slots = slots;
+	return PyModuleDef_Init(&module_def);
 }
diff --git a/src/calibre/utils/lzx/lzxmodule.c b/src/calibre/utils/lzx/lzxmodule.c
index fd19975674..6b8910e563 100644
--- a/src/calibre/utils/lzx/lzxmodule.c
+++ b/src/calibre/utils/lzx/lzxmodule.c
@@ -203,27 +203,9 @@ static PyMethodDef lzx_methods[] = {
     { NULL }
 };
 
-static struct PyModuleDef lzx_module = {
-    /* m_base     */ PyModuleDef_HEAD_INIT,
-    /* m_name     */ "lzx",
-    /* m_doc      */ lzx_doc,
-    /* m_size     */ -1,
-    /* m_methods  */ lzx_methods,
-    /* m_slots    */ 0,
-    /* m_traverse */ 0,
-    /* m_clear    */ 0,
-    /* m_free     */ 0,
-};
-
-CALIBRE_MODINIT_FUNC PyInit_lzx(void) {
-    if (PyType_Ready(&CompressorType) < 0) {
-        return NULL;
-    }
-
-    PyObject *m = PyModule_Create(&lzx_module);
-    if (m == NULL) {
-        return NULL;
-    }
+static int
+exec_module(PyObject *m) {
+    if (PyType_Ready(&CompressorType) < 0) return -1;
 
     LZXError = PyErr_NewException("lzx.LZXError", NULL, NULL);
     Py_INCREF(LZXError);
@@ -232,5 +214,17 @@ CALIBRE_MODINIT_FUNC PyInit_lzx(void) {
     Py_INCREF(&CompressorType);
     PyModule_AddObject(m, "Compressor", (PyObject *)&CompressorType);
 
-    return m;
+	return 0;
 }
+
+static PyModuleDef_Slot slots[] = { {Py_mod_exec, exec_module}, {0, NULL} };
+
+static struct PyModuleDef module_def = {
+    .m_base     = PyModuleDef_HEAD_INIT,
+    .m_name     = "lzx",
+    .m_doc      = lzx_doc,
+    .m_methods  = lzx_methods,
+    .m_slots    = slots,
+};
+
+CALIBRE_MODINIT_FUNC PyInit_lzx(void) { return PyModuleDef_Init(&module_def); }
diff --git a/src/calibre/utils/msdes/msdesmodule.c b/src/calibre/utils/msdes/msdesmodule.c
index 01fd995011..dd9145ac95 100644
--- a/src/calibre/utils/msdes/msdesmodule.c
+++ b/src/calibre/utils/msdes/msdesmodule.c
@@ -77,29 +77,25 @@ static PyMethodDef msdes_methods[] = {
     { NULL, NULL }
 };
 
-static struct PyModuleDef msdes_module = {
-    /* m_base     */ PyModuleDef_HEAD_INIT,
-    /* m_name     */ "msdes",
-    /* m_doc      */ msdes_doc,
-    /* m_size     */ -1,
-    /* m_methods  */ msdes_methods,
-    /* m_slots    */ 0,
-    /* m_traverse */ 0,
-    /* m_clear    */ 0,
-    /* m_free     */ 0,
-};
-
-CALIBRE_MODINIT_FUNC PyInit_msdes(void) {
-    PyObject *m = PyModule_Create(&msdes_module);
-    if (m == NULL) {
-        return NULL;
-    }
-
+static int
+exec_module(PyObject *m) {
     MsDesError = PyErr_NewException("msdes.MsDesError", NULL, NULL);
     Py_INCREF(MsDesError);
     PyModule_AddObject(m, "MsDesError", MsDesError);
     PyModule_AddObject(m, "EN0", PyLong_FromLong(EN0));
     PyModule_AddObject(m, "DE1", PyLong_FromLong(DE1));
 
-    return m;
+	return 0;
 }
+
+static PyModuleDef_Slot slots[] = { {Py_mod_exec, exec_module}, {0, NULL} };
+
+static struct PyModuleDef module_def = {
+    .m_base     = PyModuleDef_HEAD_INIT,
+    .m_name     = "msdes",
+    .m_doc      = msdes_doc,
+    .m_methods  = msdes_methods,
+    .m_slots    = slots,
+};
+
+CALIBRE_MODINIT_FUNC PyInit_msdes(void) { return PyModuleDef_Init(&module_def); }