diff --git a/Makefile b/Makefile
index e285aa02..92ac48c4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 localversion = $(shell bash scripts/localversion.sh)
 
-cflags = -Wall -Iinclude -Iinclude/asm/gameboy -DLOCALVERSION=\"$(localversion)\" -g -std=c99
+cflags = -Wall -Iinclude -Iinclude/asm/gameboy -DLOCALVERSION=\"$(localversion)\" -g -std=c99 -D_POSIX_C_SOURCE=200112L
 
 all:
 
diff --git a/src/fix/main.c b/src/fix/main.c
index 35af6e8e..1dcdc520 100644
--- a/src/fix/main.c
+++ b/src/fix/main.c
@@ -9,6 +9,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sysexits.h>
+#include <unistd.h>
 
 #include "asmotor.h"