diff --git a/jedec.h b/jedec.h
index 2a9f977..210f9f9 100644
--- a/jedec.h
+++ b/jedec.h
@@ -1,21 +1,21 @@
 #ifndef __JEDEC_H__
 #define __JEDEC_H__ 1
-int write_byte_program_jedec(volatile unsigned char *bios, unsigned char *src,
-			     volatile unsigned char *dst);
+int write_byte_program_jedec(volatile uint8_t *bios, uint8_t *src,
+			     volatile uint8_t *dst);
 
 extern int probe_jedec(struct flashchip *flash);
 extern int erase_chip_jedec(struct flashchip *flash);
-extern int write_jedec(struct flashchip *flash, unsigned char *buf);
-extern int erase_sector_jedec(volatile unsigned char *bios, unsigned int page);
-extern int erase_block_jedec(volatile unsigned char *bios, unsigned int page);
-extern int write_sector_jedec(volatile unsigned char *bios, unsigned char *src,
-			      volatile unsigned char *dst,
+extern int write_jedec(struct flashchip *flash, uint8_t *buf);
+extern int erase_sector_jedec(volatile uint8_t *bios, unsigned int page);
+extern int erase_block_jedec(volatile uint8_t *bios, unsigned int page);
+extern int write_sector_jedec(volatile uint8_t *bios, uint8_t *src,
+			      volatile uint8_t *dst,
 			      unsigned int page_size);
 
-extern __inline__ void toggle_ready_jedec(volatile char *dst)
+extern __inline__ void toggle_ready_jedec(volatile uint8_t *dst)
 {
 	unsigned int i = 0;
-	char tmp1, tmp2;
+	uint8_t tmp1, tmp2;
 
 	tmp1 = *dst & 0x40;
 
@@ -28,10 +28,10 @@
 	}
 }
 
-extern __inline__ void data_polling_jedec(volatile char *dst, char data)
+extern __inline__ void data_polling_jedec(volatile uint8_t *dst, uint8_t data)
 {
 	unsigned int i = 0;
-	char tmp;
+	uint8_t tmp;
 
 	data &= 0x80;
 
@@ -43,23 +43,23 @@
 	}
 }
 
-extern __inline__ void unprotect_jedec(volatile char *bios)
+extern __inline__ void unprotect_jedec(volatile uint8_t *bios)
 {
-	*(volatile char *) (bios + 0x5555) = 0xAA;
-	*(volatile char *) (bios + 0x2AAA) = 0x55;
-	*(volatile char *) (bios + 0x5555) = 0x80;
-	*(volatile char *) (bios + 0x5555) = 0xAA;
-	*(volatile char *) (bios + 0x2AAA) = 0x55;
-	*(volatile char *) (bios + 0x5555) = 0x20;
+	*(volatile uint8_t *) (bios + 0x5555) = 0xAA;
+	*(volatile uint8_t *) (bios + 0x2AAA) = 0x55;
+	*(volatile uint8_t *) (bios + 0x5555) = 0x80;
+	*(volatile uint8_t *) (bios + 0x5555) = 0xAA;
+	*(volatile uint8_t *) (bios + 0x2AAA) = 0x55;
+	*(volatile uint8_t *) (bios + 0x5555) = 0x20;
 
 	usleep(200);
 }
 
-extern __inline__ void protect_jedec(volatile char *bios)
+extern __inline__ void protect_jedec(volatile uint8_t *bios)
 {
-	*(volatile char *) (bios + 0x5555) = 0xAA;
-	*(volatile char *) (bios + 0x2AAA) = 0x55;
-	*(volatile char *) (bios + 0x5555) = 0xA0;
+	*(volatile uint8_t *) (bios + 0x5555) = 0xAA;
+	*(volatile uint8_t *) (bios + 0x2AAA) = 0x55;
+	*(volatile uint8_t *) (bios + 0x5555) = 0xA0;
 
 	usleep(200);
 }