http://www.riverbankcomputing.co.uk/hg/sip/rev/3d0336c32dfa
http://www.riverbankcomputing.co.uk/hg/sip/rev/df42f6bf92c8

--- siplib/sip.h.in
+++ siplib/sip.h.in
@@ -1553,9 +1553,13 @@
 
 #define sipIsExactWrappedType(wt)   (sipTypeAsPyTypeObject((wt)->type) == (PyTypeObject *)(wt))
 
-#define sipConvertFromSliceObject(o,len,start,stop,step,slen) \
+#if PY_VERSION_HEX >= 0x03020000
+#define sipConvertFromSliceObject   PySlice_GetIndicesEx
+#else
+#define sipConvertFromSliceObject(o, len, start, stop, step, slen) \
         PySlice_GetIndicesEx((PySliceObject *)(o), (len), (start), (stop), \
                 (step), (slen))
+#endif
 
 
 /*
--- siplib/siplib.c.in
+++ siplib/siplib.c.in
@@ -9216,9 +9216,9 @@
     const sipClassTypeDef *ctd;
 
     if ((ptr = getPtrTypeDef(self, &ctd)) == NULL)
-        return -1;
+        return;
 
-    return ctd->ctd_releasebuffer((PyObject *)self, ptr, buf);
+    ctd->ctd_releasebuffer((PyObject *)self, ptr, buf);
 }
 #endif
 
@@ -10686,7 +10686,11 @@
     if ((wc = sip_api_malloc(ulen * sizeof (wchar_t))) == NULL)
         return -1;
 
+#if PY_VERSION_HEX >= 0x03020000
+    ulen = PyUnicode_AsWideChar(obj, wc, ulen);
+#else
     ulen = PyUnicode_AsWideChar((PyUnicodeObject *)obj, wc, ulen);
+#endif
 
     if (ulen < 0)
     {
@@ -10737,7 +10741,11 @@
     if (PyUnicode_GET_SIZE(obj) != 1)
         return -1;
 
+#if PY_VERSION_HEX >= 0x03020000
+    if (PyUnicode_AsWideChar(obj, ap, 1) != 1)
+#else
     if (PyUnicode_AsWideChar((PyUnicodeObject *)obj, ap, 1) != 1)
+#endif
         return -1;
 
     return 0;
@@ -10793,7 +10801,11 @@
     if ((wc = sip_api_malloc((ulen + 1) * sizeof (wchar_t))) == NULL)
         return -1;
 
+#if PY_VERSION_HEX >= 0x03020000
+    ulen = PyUnicode_AsWideChar(obj, wc, ulen);
+#else
     ulen = PyUnicode_AsWideChar((PyUnicodeObject *)obj, wc, ulen);
+#endif
 
     if (ulen < 0)
     {
--- siplib/voidptr.c
+++ siplib/voidptr.c
@@ -429,7 +429,7 @@
     {
         Py_ssize_t start, stop, step, slicelength;
 
-        if (PySlice_GetIndicesEx((PySliceObject *)key, v->size, &start, &stop, &step, &slicelength) < 0)
+        if (sipConvertFromSliceObject(key, v->size, &start, &stop, &step, &slicelength) < 0)
             return NULL;
 
         if (step != 1)
@@ -486,7 +486,7 @@
     {
         Py_ssize_t stop, step;
 
-        if (PySlice_GetIndicesEx((PySliceObject *)key, v->size, &start, &stop, &step, &size) < 0)
+        if (sipConvertFromSliceObject(key, v->size, &start, &stop, &step, &size) < 0)
             return -1;
 
         if (step != 1)