diff --git a/linux_spi.c b/linux_spi.c
index aa73c18..1ef8f2b 100644
--- a/linux_spi.c
+++ b/linux_spi.c
@@ -49,7 +49,7 @@
 static size_t max_kernel_buf_size;
 
 static int linux_spi_shutdown(void *data);
-static int linux_spi_send_command(struct flashctx *flash, unsigned int writecnt,
+static int linux_spi_send_command(const struct flashctx *flash, unsigned int writecnt,
 				  unsigned int readcnt,
 				  const unsigned char *txbuf,
 				  unsigned char *rxbuf);
@@ -183,7 +183,7 @@
 	return 0;
 }
 
-static int linux_spi_send_command(struct flashctx *flash, unsigned int writecnt,
+static int linux_spi_send_command(const struct flashctx *flash, unsigned int writecnt,
 				  unsigned int readcnt,
 				  const unsigned char *txbuf,
 				  unsigned char *rxbuf)