diff --git a/src/proto/usercmd.pro b/src/proto/usercmd.pro
index d24e9ad..9e16a80 100644
--- a/src/proto/usercmd.pro
+++ b/src/proto/usercmd.pro
@@ -15,6 +15,6 @@
 void uc_clear(garray_T *gap);
 void ex_delcommand(exarg_T *eap);
 size_t add_win_cmd_modifers(char_u *buf, cmdmod_T *cmod, int *multi_mods);
-int produce_cmdmods(char_u *buf, cmdmod_T *cmod, int quote);
+size_t produce_cmdmods(char_u *buf, cmdmod_T *cmod, int quote);
 void do_ucmd(exarg_T *eap);
 /* vim: set ft=c : */