diff --git a/src/proto.h b/src/proto.h
index 452f9e2..c358a1d 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -177,6 +177,11 @@
 # include "mouse.pro"
 # include "move.pro"
 # include "mbyte.pro"
+# ifdef VIMDLL
+// Function name differs when VIMDLL is defined
+int mbyte_im_get_status(void);
+void mbyte_im_set_active(int active_arg);
+# endif
 # include "normal.pro"
 # include "ops.pro"
 # include "option.pro"