--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -91,6 +91,14 @@
 #include <alloca.h>
 #endif
 
+/* NuttX errno.h defines get_errno() and set_errno(e) as macros.
+   Undef them so that CPython's static functions of the same name
+   in this file compile without conflict. */
+#ifdef __NuttX__
+#undef get_errno
+#undef set_errno
+#endif
+
 #ifdef _Py_MEMORY_SANITIZER
 #include <sanitizer/msan_interface.h>
 #endif