diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 8c44ad205b..3f9a032836 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -4148,6 +4148,39 @@ test_pyobject_fastcallkeywords(PyObject *self, PyObject *args)
     return _PyObject_FastCallKeywords(func, stack, nargs, kwnames);
 }
 
+static void* nomem_malloc (void* ctx, size_t size)
+{
+    return PyErr_NoMemory();
+}
+
+static void* nomem_calloc (void* ctx, size_t nelem, size_t elsize)
+{
+    return PyErr_NoMemory();
+}
+
+static void* nomem_realloc (void* ctx, void* ptr, size_t new_size)
+{
+    return PyErr_NoMemory();
+}
+
+static void nomem_free (void *ctx, void *ptr) {}
+
+static PyMemAllocatorEx nomemory_allocator;
+
+static PyObject *
+set_nomemory_allocator(PyObject *self)
+{
+    nomemory_allocator.ctx = NULL;
+    nomemory_allocator.malloc = &nomem_malloc;
+    nomemory_allocator.calloc = &nomem_calloc;
+    nomemory_allocator.realloc = &nomem_realloc;
+    nomemory_allocator.free = &nomem_free;
+    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &nomemory_allocator);
+    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &nomemory_allocator);
+    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &nomemory_allocator);
+    Py_RETURN_NONE;
+}
+
 
 static PyMethodDef TestMethods[] = {
     {"raise_exception",         raise_exception,                 METH_VARARGS},
@@ -4353,6 +4386,7 @@ static PyMethodDef TestMethods[] = {
     {"tracemalloc_untrack", tracemalloc_untrack, METH_VARARGS},
     {"tracemalloc_get_traceback", tracemalloc_get_traceback, METH_VARARGS},
     {"dict_get_version", dict_get_version, METH_VARARGS},
+    {"set_nomemory_allocator",   (PyCFunction)set_nomemory_allocator,  METH_NOARGS},
     {"raise_SIGINT_then_send_None", raise_SIGINT_then_send_None, METH_VARARGS},
     {"pyobject_fastcall", test_pyobject_fastcall, METH_VARARGS},
     {"pyobject_fastcalldict", test_pyobject_fastcalldict, METH_VARARGS},