diff --git a/Lib/test/test_structmembers.py b/Lib/test/test_structmembers.py
index 93e040c..145a16e 100644
--- a/Lib/test/test_structmembers.py
+++ b/Lib/test/test_structmembers.py
@@ -3,13 +3,25 @@
     SHRT_MAX, SHRT_MIN, USHRT_MAX, \
     INT_MAX, INT_MIN, UINT_MAX, \
     LONG_MAX, LONG_MIN, ULONG_MAX, \
-    LLONG_MAX, LLONG_MIN, ULLONG_MAX
+    LLONG_MAX, LLONG_MIN, ULLONG_MAX, \
+    PY_SSIZE_T_MAX, PY_SSIZE_T_MIN
 
 import warnings, unittest, sys
 from test import support
 
-ts=test_structmembersType(False, 1, 2, 3, 4, 5, 6, 7, 8,
-                          9.99999, 10.1010101010)
+ts=test_structmembersType(False,  # T_BOOL
+                          1,      # T_BYTE
+                          2,      # T_UBYTE
+                          3,      # T_SHORT
+                          4,      # T_USHORT
+                          5,      # T_INT
+                          6,      # T_UINT
+                          7,      # T_LONG
+                          8,      # T_ULONG
+                          23,     # T_PYSSIZET
+                          9.99999,# T_FLOAT
+                          10.1010101010 # T_DOUBLE
+                          )
 
 class ReadWriteTests(unittest.TestCase):
     def test_types(self):
@@ -47,6 +59,11 @@
         ts.T_ULONG = ULONG_MAX
         self.assertEquals(ts.T_ULONG, ULONG_MAX)
 
+        ts.T_PYSSIZET = PY_SSIZE_T_MAX
+        self.assertEquals(ts.T_PYSSIZET, PY_SSIZE_T_MAX)
+        ts.T_PYSSIZET = PY_SSIZE_T_MIN
+        self.assertEquals(ts.T_PYSSIZET, PY_SSIZE_T_MIN)
+
         ## T_LONGLONG and T_ULONGLONG may not be present on some platforms
         if hasattr(ts, 'T_LONGLONG'):
             ts.T_LONGLONG = LLONG_MAX
@@ -63,6 +80,27 @@
             ts.T_ULONGLONG = 4
             self.assertEquals(ts.T_ULONGLONG, 4)
 
+    def test_bad_assignments(self):
+        # XXX testing of T_UINT and T_ULONG temporarily disabled;
+        # see issue 8014.
+        integer_attributes = [
+            'T_BOOL',
+            'T_BYTE', 'T_UBYTE',
+            'T_SHORT', 'T_USHORT',
+            'T_INT', #'T_UINT',
+            'T_LONG', #'T_ULONG',
+            'T_PYSSIZET'
+            ]
+
+        if hasattr(ts, 'T_LONGLONG'):
+            integer_attributes.extend(['T_LONGLONG', 'T_ULONGLONG'])
+
+        # issue8014: this produced 'bad argument to internal function'
+        # internal error
+        for nonint in None, 3.2j, "full of eels", {}, []:
+            for attr in integer_attributes:
+                self.assertRaises(TypeError, setattr, ts, attr, nonint)
+
 
 class TestWarnings(unittest.TestCase):
     def has_warned(self, w):
diff --git a/Misc/NEWS b/Misc/NEWS
index 348d524..e40100b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #8014: Setting a T_UINT or T_PYSSIZET attribute of an object with
+  PyMemberDefs could produce an internal error;  raise TypeError instead.
+
 - Issue #7845: Rich comparison methods on the complex type now return
   NotImplemented rather than raising a TypeError when comparing with an
   incompatible type; this allows user-defined classes to implement their own
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 3824388..1be3c66 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -2084,6 +2084,7 @@
 	unsigned int uint_member;
 	long long_member;
 	unsigned long ulong_member;
+	Py_ssize_t pyssizet_member;
 	float float_member;
 	double double_member;
 #ifdef HAVE_LONG_LONG
@@ -2107,6 +2108,7 @@
 	{"T_UINT", T_UINT, offsetof(test_structmembers, structmembers.uint_member), 0, NULL},
 	{"T_LONG", T_LONG, offsetof(test_structmembers, structmembers.long_member), 0, NULL},
 	{"T_ULONG", T_ULONG, offsetof(test_structmembers, structmembers.ulong_member), 0, NULL},
+	{"T_PYSSIZET", T_PYSSIZET, offsetof(test_structmembers, structmembers.pyssizet_member), 0, NULL},
 	{"T_FLOAT", T_FLOAT, offsetof(test_structmembers, structmembers.float_member), 0, NULL},
 	{"T_DOUBLE", T_DOUBLE, offsetof(test_structmembers, structmembers.double_member), 0, NULL},
 #ifdef HAVE_LONG_LONG
@@ -2122,13 +2124,13 @@
 {
 	static char *keywords[] = {
 		"T_BOOL", "T_BYTE", "T_UBYTE", "T_SHORT", "T_USHORT",
-		"T_INT", "T_UINT", "T_LONG", "T_ULONG",
+		"T_INT", "T_UINT", "T_LONG", "T_ULONG", "T_PYSSIZET",
 		"T_FLOAT", "T_DOUBLE",
-#ifdef HAVE_LONG_LONG	
+#ifdef HAVE_LONG_LONG
 		"T_LONGLONG", "T_ULONGLONG",
 #endif
 		NULL};
-	static char *fmt = "|bbBhHiIlkfd"
+	static char *fmt = "|bbBhHiIlknfd"
 #ifdef HAVE_LONG_LONG
 		"LK"
 #endif
@@ -2145,9 +2147,10 @@
 					 &ob->structmembers.short_member,
 					 &ob->structmembers.ushort_member,
 					 &ob->structmembers.int_member,
-					 &ob->structmembers.uint_member, 
+					 &ob->structmembers.uint_member,
 					 &ob->structmembers.long_member,
 					 &ob->structmembers.ulong_member,
+					 &ob->structmembers.pyssizet_member,
 					 &ob->structmembers.float_member,
 					 &ob->structmembers.double_member
 #ifdef HAVE_LONG_LONG
diff --git a/Objects/longobject.c b/Objects/longobject.c
index ce87084..d182e7c 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -435,10 +435,15 @@
 	Py_ssize_t i;
 	int sign;
 
-	if (vv == NULL || !PyLong_Check(vv)) {
+	if (vv == NULL) {
 		PyErr_BadInternalCall();
 		return -1;
 	}
+	if (!PyLong_Check(vv)) {
+		PyErr_SetString(PyExc_TypeError, "an integer is required");
+		return -1;
+	}
+
 	v = (PyLongObject *)vv;
 	i = Py_SIZE(v);
 	switch (i) {
@@ -485,10 +490,15 @@
 	unsigned long x, prev;
 	Py_ssize_t i;
 
-	if (vv == NULL || !PyLong_Check(vv)) {
+	if (vv == NULL) {
 		PyErr_BadInternalCall();
-		return (unsigned long) -1;
+		return (unsigned long)-1;
 	}
+	if (!PyLong_Check(vv)) {
+		PyErr_SetString(PyExc_TypeError, "an integer is required");
+		return (unsigned long)-1;
+	}
+
 	v = (PyLongObject *)vv;
 	i = Py_SIZE(v);
 	x = 0;
@@ -523,10 +533,15 @@
 	size_t x, prev;
 	Py_ssize_t i;
 
-	if (vv == NULL || !PyLong_Check(vv)) {
+	if (vv == NULL) {
 		PyErr_BadInternalCall();
-		return (unsigned long) -1;
+		return (size_t) -1;
 	}
+	if (!PyLong_Check(vv)) {
+		PyErr_SetString(PyExc_TypeError, "an integer is required");
+		return (size_t)-1;
+	}
+
 	v = (PyLongObject *)vv;
 	i = Py_SIZE(v);
 	x = 0;