diff --git a/src/common/libremoteio.h b/src/common/libremoteio.h
--- a/src/common/libremoteio.h
+++ b/src/common/libremoteio.h
@@ -117,7 +117,7 @@ struct remoteio
 /* lookup table */
 typedef int remoteio_open_func_t(struct remoteio *rem, struct remoteio_server *server);
 typedef int remoteio_read_func_t(struct remoteio *rem, void *buf, size_t len, size_t *bytesread);
-typedef int remoteio_write_func_t(struct remoteio *rem, void *buf, size_t len, size_t *bytesread);
+typedef int remoteio_write_func_t(struct remoteio *rem, const void *buf, size_t len, size_t *bytesread);
 typedef int remoteio_close_func_t(struct remoteio *rem);
 
 struct remoteio_method_funcmap