1 files changed, 2 insertions, 0 deletions
diff --git a/internal.h b/internal.h
index ca4220a841..4e39e47f75 100644
--- a/internal.h
+++ b/internal.h
@@ -25,6 +25,8 @@ struct rb_classext_struct {
     struct st_table *const_tbl;
 };
 
+VALUE rb_big_uminus(VALUE x);
+
 #if defined(__cplusplus)
 #if 0
 { /* satisfy cc-mode */