diff --git a/flash.h b/flash.h
index 1a9bd9f..2f0143b 100644
--- a/flash.h
+++ b/flash.h
@@ -415,8 +415,8 @@
 	unsigned char *readarr;
 };
 #define NULL_SPI_CMD { 0, 0, NULL, NULL, }
-int spi_send_command(struct flashctx *flash, unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr);
-int spi_send_multicommand(struct flashctx *flash, struct spi_command *cmds);
+int spi_send_command(const struct flashctx *flash, unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr);
+int spi_send_multicommand(const struct flashctx *flash, struct spi_command *cmds);
 
 enum chipbustype get_buses_supported(void);
 #endif				/* !__FLASH_H__ */