diff --git a/mdig/Makefile b/mdig/Makefile
index 588344d..85b45c8 100644
--- a/mdig/Makefile
+++ b/mdig/Makefile
@@ -1,6 +1,6 @@
 CC ?= gcc
 CFLAGS += -s -O3
-LIBS = 
+LIBS = -lpthread
 SRC_FILES = *.c
 
 all: mdig
diff --git a/mdig/mdig.c b/mdig/mdig.c
index 3822f9a..3996b00 100644
--- a/mdig/mdig.c
+++ b/mdig/mdig.c
@@ -3,6 +3,8 @@
 // ip list >stdout
 // errors, verbose >stderr
 
+#define _GNU_SOURCE
+
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>