diff --git a/src/backend/port/inet_aton.c b/src/backend/port/inet_aton.c
index 0220507a523..dd7bb5d16d5 100644
--- a/src/backend/port/inet_aton.c
+++ b/src/backend/port/inet_aton.c
@@ -47,6 +47,10 @@
 #include <ctype.h>
 #include "inet_aton.h"
 
+#ifdef _AIX
+#include <sys/ltypes.h>	/* For definition of uint32 */
+#endif
+
 /*
  * Check whether "cp" is a valid ascii representation
  * of an Internet address and convert to a binary address.