diff -U 3 -dHrN a/libwcs/dateutil.c b/libwcs/dateutil.c
--- a/libwcs/dateutil.c	2021-09-15 23:45:06.000000000 +0200
+++ b/libwcs/dateutil.c	2025-01-24 09:38:40.402443820 +0100
@@ -314,6 +314,8 @@
  *	Return Mod of floating point number
  */
 
+#define _GNU_SOURCE
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
diff -U 3 -dHrN a/libwcs/imgetwcs.c b/libwcs/imgetwcs.c
--- a/libwcs/imgetwcs.c	2016-06-24 21:23:06.000000000 +0200
+++ b/libwcs/imgetwcs.c	2025-01-24 09:40:12.971028438 +0100
@@ -31,6 +31,7 @@
 #include <stdlib.h>
 #include <math.h>
 #include <string.h>
+#include <strings.h>
 
 #include "wcs.h"
 #include "lwcs.h"
diff -U 3 -dHrN a/libwcs/webread.c b/libwcs/webread.c
--- a/libwcs/webread.c	2022-02-04 22:08:59.000000000 +0100
+++ b/libwcs/webread.c	2025-01-24 09:37:25.750042386 +0100
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <strings.h>
 #include <math.h>
 #include <ctype.h>
 #include "wcs.h"
@@ -976,7 +977,7 @@
     memset(adrinet, 0, sizeof(struct sockaddr_in));
     adrinet->sin_family = AF_INET;
     adrinet->sin_port = htons(port);
-    memcpy(&adrinet->sin_addr, hp->h_addr, hp->h_length);
+    memcpy(&adrinet->sin_addr, hp->h_addr_list[0], hp->h_length);
 
     return type;
 }
diff -U 3 -dHrN a/Makefile b/Makefile
--- a/Makefile	2025-01-22 08:49:29.246196532 +0100
+++ b/Makefile	2025-01-24 09:31:30.842906462 +0100
@@ -1,4 +1,7 @@
 CC= gcc
+
+CFLAGS += -std=c99 -D_XOPEN_SOURCE=500
+
 LIBWCS = libwcs/libwcstools.so
 LIBS = -L libwcs -lwcstools -lm
 #LIBS = $(LIBWCS) -lm -lnsl -lsocket