--- ./src/fd.cc.orig	2024-01-24 05:44:44.801180934 +0000
+++ ./src/fd.cc	2024-01-24 05:46:19.441219270 +0000
@@ -8,6 +8,10 @@
 
 /* DEBUG: section 51    Filedescriptor Functions */
 
+#ifdef _AIX
+ #define MSG_DONTWAIT MSG_NONBLOCK
+#endif
+
 #include "squid.h"
 #include "comm/Loops.h"
 #include "debug/Messages.h"