diff --git a/libcpu/arm/s3c24x0/s3c24x0.h b/libcpu/arm/s3c24x0/s3c24x0.h
index 3560c2b92f1ae3b90fc910fc5d7c900e40156704..c5de9ee396035bf61bbbb48f6c11d157bf7db0a5 100644
--- a/libcpu/arm/s3c24x0/s3c24x0.h
+++ b/libcpu/arm/s3c24x0/s3c24x0.h
@@ -131,14 +131,14 @@ extern "C" {
 
 // NAND flash
 #define NFCONF     (*(volatile unsigned *)0x4e000000)      //NAND Flash configuration
-#define NFCMD      (*(volatile U8 *)0x4e000004)            //NADD Flash command
-#define NFADDR     (*(volatile U8 *)0x4e000008)            //NAND Flash address
-#define NFDATA     (*(volatile U8 *)0x4e00000c)            //NAND Flash data
+#define NFCMD      (*(volatile unsigned *)0x4e000004)            //NADD Flash command
+#define NFADDR     (*(volatile unsigned *)0x4e000008)            //NAND Flash address
+#define NFDATA     (*(volatile unsigned *)0x4e00000c)            //NAND Flash data
 #define NFSTAT     (*(volatile unsigned *)0x4e000010)      //NAND Flash operation status
 #define NFECC      (*(volatile unsigned *)0x4e000014)      //NAND Flash ECC
-#define NFECC0     (*(volatile U8  *)0x4e000014)
-#define NFECC1     (*(volatile U8  *)0x4e000015)
-#define NFECC2     (*(volatile U8  *)0x4e000016)
+#define NFECC0     (*(volatile unsigned *)0x4e000014)
+#define NFECC1     (*(volatile unsigned *)0x4e000015)
+#define NFECC2     (*(volatile unsigned *)0x4e000016)
 
 // UART
 #define U0BASE     (*(volatile unsigned *)0x50000000) //UART 0 Line control