diff --git a/src/proto/if_mzsch.pro b/src/proto/if_mzsch.pro
index 193bd49..bab82ce 100644
--- a/src/proto/if_mzsch.pro
+++ b/src/proto/if_mzsch.pro
@@ -3,7 +3,7 @@
 void mzvim_check_threads(void);
 void mzvim_reset_timer(void);
 void mzscheme_end(void);
-int mzscheme_main(int argc, char **argv);
+int mzscheme_main(void);
 void mzscheme_buffer_free(buf_T *buf);
 void mzscheme_window_free(win_T *win);
 void ex_mzscheme(exarg_T *eap);