diff --git a/Misc/NEWS b/Misc/NEWS
index 505fab58209..769b80e7307 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -54,6 +54,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #18561: Skip name in ctypes' _build_callargs() if name is NULL.
+
 - Issue #18559: Fix NULL pointer dereference error in _pickle module
 
 - Issue #18556: Check the return value of a PyUnicode_AsWideChar() call in
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index a025a732f6d..9a37aacf0cb 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -3453,7 +3453,7 @@ _get_arg(int *pindex, PyObject *name, PyObject *defval, PyObject *inargs, PyObje
         Py_INCREF(v);
         return v;
     }
-    if (kwds && (v = PyDict_GetItem(kwds, name))) {
+    if (kwds && name && (v = PyDict_GetItem(kwds, name))) {
         ++*pindex;
         Py_INCREF(v);
         return v;