diff --git a/src/proto/os_amiga.pro b/src/proto/os_amiga.pro
index 479297d..4ac96aa 100644
--- a/src/proto/os_amiga.pro
+++ b/src/proto/os_amiga.pro
@@ -25,7 +25,7 @@
 extern int mch_setperm __ARGS((char_u *name, long perm));
 extern void mch_hide __ARGS((char_u *name));
 extern int mch_isdir __ARGS((char_u *name));
-extern void mch_mkdir __ARGS((char_u *name));
+extern int mch_mkdir __ARGS((char_u *name));
 extern int mch_can_exe __ARGS((char_u *name));
 extern int mch_nodetype __ARGS((char_u *name));
 extern void mch_early_init __ARGS((void));