diff --git a/Makefile b/Makefile
index 63882e7..ed39f9b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 
 CPPFLAGS=-DHAS_BLKID
-CFLAGS=-O3
+CFLAGS=-O3 -Wall
 LDLIBS=-lblkid
 
 all: abootimg
diff --git a/abootimg.c b/abootimg.c
index 381fa23..464522f 100644
--- a/abootimg.c
+++ b/abootimg.c
@@ -24,6 +24,7 @@
 #include <stdarg.h>
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 
 #ifdef __linux__