diff --git a/include/extern.h b/include/extern.h
index 8a024a3db..eb492c320 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -2263,7 +2263,7 @@ E void FDECL(skill_init, (const struct def_skill *));
 
 E void FDECL(were_change, (struct monst *));
 E void FDECL(new_were, (struct monst *));
-E boolean FDECL(were_summon, (struct permonst *,BOOLEAN_P));
+E int FDECL(were_summon, (struct permonst *,BOOLEAN_P,int *));
 E void NDECL(you_were);
 E void FDECL(you_unwere, (BOOLEAN_P));