diff --git a/src/calibre/devices/mtp/windows/device_enumeration.cpp b/src/calibre/devices/mtp/windows/device_enumeration.cpp
index c06c33d403..f0030d0576 100644
--- a/src/calibre/devices/mtp/windows/device_enumeration.cpp
+++ b/src/calibre/devices/mtp/windows/device_enumeration.cpp
@@ -220,7 +220,7 @@ PyObject* get_device_information(IPortableDevice *device, IPortableDevicePropert
     LPWSTR temp;
     ULONG ti;
     PyObject *t, *ans = NULL, *storage = NULL;
-    char *type;
+    const char *type = NULL;
 
     Py_BEGIN_ALLOW_THREADS;
     hr = CoCreateInstance(CLSID_PortableDeviceKeyCollection, NULL,
@@ -302,7 +302,11 @@ PyObject* get_device_information(IPortableDevice *device, IPortableDevicePropert
             default:
                 type = "unknown";
         }
+#if PY_MAJOR_VERSION >= 3
+        t = PyUnicode_FromString(type);
+#else
         t = PyString_FromString(type);
+#endif
         if (t != NULL) {
             PyDict_SetItemString(ans, "type", t); Py_DECREF(t);
         }
diff --git a/src/calibre/utils/podofo/utils.cpp b/src/calibre/utils/podofo/utils.cpp
index 668ae83e3d..dd934b7f3d 100644
--- a/src/calibre/utils/podofo/utils.cpp
+++ b/src/calibre/utils/podofo/utils.cpp
@@ -18,15 +18,14 @@ void pdf::podofo_set_exception(const PdfError &err) {
 PyObject *
 pdf::podofo_convert_pdfstring(const PdfString &s) {
     std::string raw = s.GetStringUtf8();
-	return PyString_FromStringAndSize(raw.c_str(), raw.length());
+	return PyBytes_FromStringAndSize(raw.c_str(), raw.length());
 }
 
 PdfString *
 pdf::podofo_convert_pystring(PyObject *py) {
-    Py_UNICODE* u = PyUnicode_AS_UNICODE(py);
-    PyObject *u8 = PyUnicode_EncodeUTF8(u, PyUnicode_GET_SIZE(py), "replace");
-    if (u8 == NULL) { PyErr_NoMemory(); return NULL; }
-    pdf_utf8 *s8 = reinterpret_cast<pdf_utf8 *>(PyString_AS_STRING(u8));
+    PyObject *u8 = PyUnicode_AsEncodedString(py, "UTF-8", "replace");
+    if (u8 == NULL) { return NULL; }
+    pdf_utf8 *s8 = reinterpret_cast<pdf_utf8 *>(PyBytes_AS_STRING(u8));
     PdfString *ans = new PdfString(s8);
     Py_DECREF(u8);
     if (ans == NULL) PyErr_NoMemory();
@@ -35,10 +34,9 @@ pdf::podofo_convert_pystring(PyObject *py) {
 
 PdfString *
 pdf::podofo_convert_pystring_single_byte(PyObject *py) {
-    Py_UNICODE* u = PyUnicode_AS_UNICODE(py);
-    PyObject *s = PyUnicode_Encode(u, PyUnicode_GET_SIZE(py), "cp1252", "replace");
-    if (s == NULL) { PyErr_NoMemory(); return NULL; }
-    PdfString *ans = new PdfString(PyString_AS_STRING(s));
+    PyObject *s = PyUnicode_AsEncodedString(py, "cp1252", "replace");
+    if (s == NULL) { return NULL; }
+    PdfString *ans = new PdfString(PyBytes_AS_STRING(s));
     Py_DECREF(s);
     if (ans == NULL) PyErr_NoMemory();
     return ans;