diff --git a/Modules/_testbuffer.c b/Modules/_testbuffer.c
index 43db8a8..4e1ce68 100644
--- a/Modules/_testbuffer.c
+++ b/Modules/_testbuffer.c
@@ -850,6 +850,7 @@
     Py_ssize_t *dest;
     Py_ssize_t x, i;
 
+    /* ndim = len <= ND_MAX_NDIM, so PyMem_New() is actually not needed. */
     dest = PyMem_New(Py_ssize_t, len);
     if (dest == NULL) {
         PyErr_NoMemory();