diff --git a/include/programmer.h b/include/programmer.h
index 2735467..2cb1371 100644
--- a/include/programmer.h
+++ b/include/programmer.h
@@ -273,7 +273,7 @@
 #endif
 
 /* bitbang_spi.c */
-int register_spi_bitbang_master(const struct bitbang_spi_master *master);
+int register_spi_bitbang_master(const struct bitbang_spi_master *master, void *spi_data);
 
 
 /* flashrom.c */