diff --git a/libmapper/mapper.h b/libmapper/mapper.h
index b3fed6b..9f85c5f 100644
--- a/libmapper/mapper.h
+++ b/libmapper/mapper.h
@@ -8,7 +8,7 @@
 typedef struct mapper_async_wait mapper_async_wait;
 void mapper_wait_async_free(mapper_async_wait *);
 
-int mapper_wait_async(sd_bus *, sd_event *, const char *, char *[],
+int mapper_wait_async(sd_bus *, sd_event *, char *[],
 		void (*)(int, void *), void *, mapper_async_wait **,
 		bool);
 int mapper_get_service(sd_bus *conn, const char *obj, char **service);