diff --git a/Tk/tkImaging.c b/Tk/tkImaging.c
index 5963ee24c..4234a7d2b 100644
--- a/Tk/tkImaging.c
+++ b/Tk/tkImaging.c
@@ -58,7 +58,7 @@
 static Imaging
 ImagingFind(const char* name)
 {
-    long id;
+    Py_ssize_t id;
 
     /* FIXME: use CObject instead? */
     id = atol(name);
diff --git a/_imaging.c b/_imaging.c
index 8adbe3b16..5c429aba6 100644
--- a/_imaging.c
+++ b/_imaging.c
@@ -2995,7 +2995,7 @@ _getattr_bands(ImagingObject* self, void* closure)
 static PyObject*
 _getattr_id(ImagingObject* self, void* closure)
 {
-	return PyInt_FromLong((long) self->image);
+	return PyInt_FromSsize_t((Py_ssize_t) self->image);
 }
 
 static PyObject*
diff --git a/_imagingcms.c b/_imagingcms.c
index 84ee8d824..946b8c691 100644
--- a/_imagingcms.c
+++ b/_imagingcms.c
@@ -376,14 +376,14 @@ buildProofTransform(PyObject *self, PyObject *args)
 static PyObject *
 cms_transform_apply(CmsTransformObject *self, PyObject *args)
 {
-    long idIn;
-    long idOut;
+    Py_ssize_t idIn;
+    Py_ssize_t idOut;
     Imaging im;
     Imaging imOut;
 
     int result;
 
-    if (!PyArg_ParseTuple(args, "ll:apply", &idIn, &idOut))
+    if (!PyArg_ParseTuple(args, "nn:apply", &idIn, &idOut))
         return NULL;
 
     im = (Imaging) idIn;
diff --git a/_imagingft.c b/_imagingft.c
index f54e38553..7028293ec 100644
--- a/_imagingft.c
+++ b/_imagingft.c
@@ -293,9 +293,9 @@ font_render(FontObject* self, PyObject* args)
     /* render string into given buffer (the buffer *must* have
        the right size, or this will crash) */
     PyObject* string;
-    long id;
+    Py_ssize_t id;
     int mask = 0;
-    if (!PyArg_ParseTuple(args, "Ol|i:render", &string, &id, &mask))
+    if (!PyArg_ParseTuple(args, "On|i:render", &string, &id, &mask))
         return NULL;
 
 #if PY_VERSION_HEX >= 0x03000000
diff --git a/_imagingmath.c b/_imagingmath.c
index c21dac1de..4f377e9ac 100644
--- a/_imagingmath.c
+++ b/_imagingmath.c
@@ -174,8 +174,8 @@ _unop(PyObject* self, PyObject* args)
     Imaging im1;
     void (*unop)(Imaging, Imaging);
 
-    long op, i0, i1;
-    if (!PyArg_ParseTuple(args, "lll", &op, &i0, &i1))
+    Py_ssize_t op, i0, i1;
+    if (!PyArg_ParseTuple(args, "nnn", &op, &i0, &i1))
         return NULL;
 
     out = (Imaging) i0;
@@ -197,8 +197,8 @@ _binop(PyObject* self, PyObject* args)
     Imaging im2;
     void (*binop)(Imaging, Imaging, Imaging);
 
-    long op, i0, i1, i2;
-    if (!PyArg_ParseTuple(args, "llll", &op, &i0, &i1, &i2))
+    Py_ssize_t op, i0, i1, i2;
+    if (!PyArg_ParseTuple(args, "nnnn", &op, &i0, &i1, &i2))
         return NULL;
 
     out = (Imaging) i0;
diff --git a/_imagingtk.c b/_imagingtk.c
index b29cfdca8..cb6f21009 100644
--- a/_imagingtk.c
+++ b/_imagingtk.c
@@ -35,9 +35,9 @@ _tkinit(PyObject* self, PyObject* args)
 {
     Tcl_Interp* interp;
 
-    long arg;
+    Py_ssize_t arg;
     int is_interp;
-    if (!PyArg_ParseTuple(args, "li", &arg, &is_interp))
+    if (!PyArg_ParseTuple(args, "ni", &arg, &is_interp))
         return NULL;
 
     if (is_interp)
diff --git a/display.c b/display.c
index 81ad329f9..bf00e49fe 100644
--- a/display.c
+++ b/display.c
@@ -399,7 +399,7 @@ static BOOL CALLBACK list_windows_callback(HWND hwnd, LPARAM lParam)
     GetWindowRect(hwnd, &outer);
 
     item = Py_BuildValue(
-        "lN(iiii)(iiii)", (long) hwnd, title,
+        "nN(iiii)(iiii)", (Py_ssize_t) hwnd, title,
         inner.left, inner.top, inner.right, inner.bottom,
         outer.left, outer.top, outer.right, outer.bottom
         );
@@ -735,15 +735,15 @@ PyImaging_CreateWindowWin32(PyObject* self, PyObject* args)
 
     /* register window callback */
     Py_INCREF(callback);
-    SetWindowLong(wnd, 0, (LONG) callback);
-    SetWindowLong(wnd, sizeof(callback), (LONG) PyThreadState_Get());
+    SetWindowLongPtr(wnd, 0, (LONG_PTR) callback);
+    SetWindowLongPtr(wnd, sizeof(callback), (LONG_PTR) PyThreadState_Get());
 
     Py_BEGIN_ALLOW_THREADS
     ShowWindow(wnd, SW_SHOWNORMAL);
     SetForegroundWindow(wnd); /* to make sure it's visible */
     Py_END_ALLOW_THREADS
 
-    return Py_BuildValue("l", (long) wnd);
+    return Py_BuildValue("n", (Py_ssize_t) wnd);
 }
 
 PyObject*