diff --git a/src/machinarium.h b/src/machinarium.h
index a707db3e..a4dd7b93 100644
--- a/src/machinarium.h
+++ b/src/machinarium.h
@@ -24,7 +24,6 @@
 
 typedef void (*machine_coroutine_t)(void *arg);
 
-typedef void* machine_t;
 typedef void* machine_msg_t;
 typedef void* machine_channel_t;
 typedef void* machine_queue_t;
@@ -50,7 +49,7 @@ machine_stop(void);
 MACHINE_API int
 machine_active(void);
 
-MACHINE_API machine_t
+MACHINE_API uint64_t
 machine_self(void);
 
 MACHINE_API int
diff --git a/src/mm_machine.c b/src/mm_machine.c
index 1575e4bb..e08f14f6 100644
--- a/src/mm_machine.c
+++ b/src/mm_machine.c
@@ -126,10 +126,10 @@ machine_active(void)
 	return mm_self->online;
 }
 
-MACHINE_API machine_t
+MACHINE_API uint64_t
 machine_self(void)
 {
-	return mm_self;
+	return mm_self->id;
 }
 
 MACHINE_API void