diff --git a/aclocal.m4 b/aclocal.m4
index c52bffc..99e6a04 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -40,6 +40,7 @@ AC_DEFUN(PA_MSGHDR_MSG_CONTROL,
 [AC_MSG_CHECKING([for msg_control in struct msghdr])
  AC_TRY_COMPILE(
 [
+#define _XPG4_2		/* Needed on Solaris */
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
diff --git a/tftpd/recvfrom.c b/tftpd/recvfrom.c
index 38eac94..fbe902b 100644
--- a/tftpd/recvfrom.c
+++ b/tftpd/recvfrom.c
@@ -18,6 +18,7 @@
  *
  */
 
+#define _XPG4_2			/* Needed on Solaris */
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
diff --git a/tftpd/recvfrom.h b/tftpd/recvfrom.h
index 3bb2b39..1de145e 100644
--- a/tftpd/recvfrom.h
+++ b/tftpd/recvfrom.h
@@ -16,6 +16,7 @@
  *
  */
 
+#define _XPG4_2			/* Needed on Solaris */
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>