diff --git a/SerialFlash.c b/SerialFlash.c
index 66bfc6a..46a6387 100644
--- a/SerialFlash.c
+++ b/SerialFlash.c
@@ -4,6 +4,7 @@
 #include "project.h"
 #include "usbdriver.h"
 #include <sys/stat.h>
+#include <stdlib.h>
 
 extern int m_isCanceled;
 extern int m_bProtectAfterWritenErase;
diff --git a/board.c b/board.c
index 7c6f5a5..1e3fa57 100644
--- a/board.c
+++ b/board.c
@@ -2,6 +2,7 @@
 #include "FlashCommand.h"
 #include "project.h"
 #include "usbdriver.h"
+#include <stdlib.h>
 #define SerialFlash_FALSE -1
 #define SerialFlash_TRUE 1
 #define min(a, b) (a > b ? b : a)
diff --git a/dpcmd.c b/dpcmd.c
index 2f97d25..bbba2f7 100644
--- a/dpcmd.c
+++ b/dpcmd.c
@@ -8,6 +8,7 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <pthread.h>
+#include <stdlib.h>
 #include <signal.h>
 #include <sys/stat.h>
 #include <sys/time.h>
diff --git a/project.c b/project.c
index e4fb27b..db0670f 100644
--- a/project.c
+++ b/project.c
@@ -8,6 +8,7 @@
 #include <ctype.h>
 #include <fcntl.h>
 #include <pthread.h>
+#include <stdlib.h>
 #include <stdint.h>
 
 #include <pthread.h>