diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 1b2ea9b7a11..17aef8faadd 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -688,7 +688,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 	}
 #ifdef Py_USING_UNICODE
 	else if (PyUnicode_Check(v)) {
-		if (PyUnicode_GET_SIZE(v) >= sizeof(s_buffer)) {
+		if (PyUnicode_GET_SIZE(v) >= (Py_ssize_t)sizeof(s_buffer)) {
 			PyErr_SetString(PyExc_ValueError,
 				 "complex() literal too large to convert");
 			return NULL;
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 5ec8a0ea385..7650ae6934f 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -97,7 +97,7 @@ PyFloat_FromString(PyObject *v, char **pend)
 	}
 #ifdef Py_USING_UNICODE
 	else if (PyUnicode_Check(v)) {
-		if (PyUnicode_GET_SIZE(v) >= sizeof(s_buffer)) {
+		if (PyUnicode_GET_SIZE(v) >= (Py_ssize_t)sizeof(s_buffer)) {
 			PyErr_SetString(PyExc_ValueError,
 				"Unicode float() literal too long to convert");
 			return NULL;
diff --git a/Objects/intobject.c b/Objects/intobject.c
index 63034bcac09..2062bee9de1 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -255,18 +255,18 @@ PyInt_AsUnsignedLongMask(register PyObject *op)
 	if (op == NULL || (nb = op->ob_type->tp_as_number) == NULL ||
 	    nb->nb_int == NULL) {
 		PyErr_SetString(PyExc_TypeError, "an integer is required");
-		return -1;
+		return (unsigned long)-1;
 	}
 
 	io = (PyIntObject*) (*nb->nb_int) (op);
 	if (io == NULL)
-		return -1;
+		return (unsigned long)-1;
 	if (!PyInt_Check(io)) {
 		if (PyLong_Check(io)) {
 			val = PyLong_AsUnsignedLongMask((PyObject *)io);
 			Py_DECREF(io);
 			if (PyErr_Occurred())
-				return -1;
+				return (unsigned long)-1;
 			return val;
 		}
 		else
@@ -274,7 +274,7 @@ PyInt_AsUnsignedLongMask(register PyObject *op)
 			Py_DECREF(io);
 			PyErr_SetString(PyExc_TypeError,
 					"nb_int should return int object");
-			return -1;
+			return (unsigned long)-1;
 		}
 	}
 
@@ -300,18 +300,18 @@ PyInt_AsUnsignedLongLongMask(register PyObject *op)
 	if (op == NULL || (nb = op->ob_type->tp_as_number) == NULL ||
 	    nb->nb_int == NULL) {
 		PyErr_SetString(PyExc_TypeError, "an integer is required");
-		return -1;
+		return (unsigned PY_LONG_LONG)-1;
 	}
 
 	io = (PyIntObject*) (*nb->nb_int) (op);
 	if (io == NULL)
-		return -1;
+		return (unsigned PY_LONG_LONG)-1;
 	if (!PyInt_Check(io)) {
 		if (PyLong_Check(io)) {
 			val = PyLong_AsUnsignedLongLongMask((PyObject *)io);
 			Py_DECREF(io);
 			if (PyErr_Occurred())
-				return -1;
+				return (unsigned PY_LONG_LONG)-1;
 			return val;
 		}
 		else
@@ -319,7 +319,7 @@ PyInt_AsUnsignedLongLongMask(register PyObject *op)
 			Py_DECREF(io);
 			PyErr_SetString(PyExc_TypeError,
 					"nb_int should return int object");
-			return -1;
+			return (unsigned PY_LONG_LONG)-1;
 		}
 	}
 
@@ -1152,6 +1152,7 @@ PyInt_Fini(void)
 	PyIntObject *p;
 	PyIntBlock *list, *next;
 	int i;
+	unsigned int ctr;
 	int bc, bf;	/* block count, number of freed blocks */
 	int irem, isum;	/* remaining unfreed ints per block, total */
 
@@ -1174,9 +1175,9 @@ PyInt_Fini(void)
 	while (list != NULL) {
 		bc++;
 		irem = 0;
-		for (i = 0, p = &list->objects[0];
-		     i < N_INTOBJECTS;
-		     i++, p++) {
+		for (ctr = 0, p = &list->objects[0];
+		     ctr < N_INTOBJECTS;
+		     ctr++, p++) {
 			if (PyInt_CheckExact(p) && p->ob_refcnt != 0)
 				irem++;
 		}
@@ -1184,9 +1185,9 @@ PyInt_Fini(void)
 		if (irem) {
 			list->next = block_list;
 			block_list = list;
-			for (i = 0, p = &list->objects[0];
-			     i < N_INTOBJECTS;
-			     i++, p++) {
+			for (ctr = 0, p = &list->objects[0];
+			     ctr < N_INTOBJECTS;
+			     ctr++, p++) {
 				if (!PyInt_CheckExact(p) ||
 				    p->ob_refcnt == 0) {
 					p->ob_type = (struct _typeobject *)
@@ -1227,9 +1228,9 @@ PyInt_Fini(void)
 	if (Py_VerboseFlag > 1) {
 		list = block_list;
 		while (list != NULL) {
-			for (i = 0, p = &list->objects[0];
-			     i < N_INTOBJECTS;
-			     i++, p++) {
+			for (ctr = 0, p = &list->objects[0];
+			     ctr < N_INTOBJECTS;
+			     ctr++, p++) {
 				if (PyInt_CheckExact(p) && p->ob_refcnt != 0)
 					/* XXX(twouters) cast refcount to
 					   long until %zd is universally
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 634252f0d71..5ac570df3f4 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -419,7 +419,7 @@ _PyLong_NumBits(PyObject *vv)
 		digit msd = v->ob_digit[ndigits - 1];
 
 		result = (ndigits - 1) * SHIFT;
-		if (result / SHIFT != ndigits - 1)
+		if (result / SHIFT != (size_t)(ndigits - 1))
 			goto Overflow;
 		do {
 			++result;
@@ -953,7 +953,7 @@ PyLong_AsUnsignedLongLong(PyObject *vv)
 
 	if (vv == NULL || !PyLong_Check(vv)) {
 		PyErr_BadInternalCall();
-		return -1;
+		return (unsigned PY_LONG_LONG)-1;
 	}
 
 	res = _PyLong_AsByteArray(
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 9d4dc7410d3..ef3b825037e 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -746,7 +746,7 @@ PyString_AsStringAndSize(register PyObject *obj,
 	*s = PyString_AS_STRING(obj);
 	if (len != NULL)
 		*len = PyString_GET_SIZE(obj);
-	else if (strlen(*s) != PyString_GET_SIZE(obj)) {
+	else if (strlen(*s) != (size_t)PyString_GET_SIZE(obj)) {
 		PyErr_SetString(PyExc_TypeError,
 				"expected string without null bytes");
 		return -1;
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 47de3022ea0..8d2bf8cbb37 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1118,12 +1118,12 @@ set_mro_error(PyObject *to_merge, int *remain)
 	off = PyOS_snprintf(buf, sizeof(buf), "Cannot create a \
 consistent method resolution\norder (MRO) for bases");
 	i = 0;
-	while (PyDict_Next(set, &i, &k, &v) && off < sizeof(buf)) {
+	while (PyDict_Next(set, &i, &k, &v) && (size_t)off < sizeof(buf)) {
 		PyObject *name = class_name(k);
 		off += PyOS_snprintf(buf + off, sizeof(buf) - off, " %s",
 				     name ? PyString_AS_STRING(name) : "?");
 		Py_XDECREF(name);
-		if (--n && off+1 < sizeof(buf)) {
+		if (--n && (size_t)(off+1) < sizeof(buf)) {
 			buf[off++] = ',';
 			buf[off] = '\0';
 		}
@@ -5186,16 +5186,16 @@ slotptr(PyTypeObject *type, int ioffset)
 
 	/* Note: this depends on the order of the members of PyHeapTypeObject! */
 	assert(offset >= 0);
-	assert(offset < offsetof(PyHeapTypeObject, as_buffer));
-	if (offset >= offsetof(PyHeapTypeObject, as_sequence)) {
+	assert((size_t)offset < offsetof(PyHeapTypeObject, as_buffer));
+	if ((size_t)offset >= offsetof(PyHeapTypeObject, as_sequence)) {
 		ptr = (char *)type->tp_as_sequence;
 		offset -= offsetof(PyHeapTypeObject, as_sequence);
 	}
-	else if (offset >= offsetof(PyHeapTypeObject, as_mapping)) {
+	else if ((size_t)offset >= offsetof(PyHeapTypeObject, as_mapping)) {
 		ptr = (char *)type->tp_as_mapping;
 		offset -= offsetof(PyHeapTypeObject, as_mapping);
 	}
-	else if (offset >= offsetof(PyHeapTypeObject, as_number)) {
+	else if ((size_t)offset >= offsetof(PyHeapTypeObject, as_number)) {
 		ptr = (char *)type->tp_as_number;
 		offset -= offsetof(PyHeapTypeObject, as_number);
 	}