diff --git a/include/common/compat.h b/include/common/compat.h
index 1bfe669..774f9b4 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -33,6 +33,7 @@
 
 /* This is needed on Linux for Netfilter includes */
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <common/config.h>
 
 /* INTBITS
@@ -54,6 +55,13 @@
 #define SHUT_WR	        1
 #endif
 
+/* AIX does not define MSG_DONTWAIT. We'll define it to zero, and test it
+ * wherever appropriate.
+ */
+#ifndef MSG_DONTWAIT
+#define MSG_DONTWAIT	0
+#endif
+
 #if defined(TPROXY) && defined(NETFILTER)
 #include <linux/netfilter_ipv4.h>
 #endif