1 files changed, 1 insertions, 0 deletions
diff --git a/regex.c b/regex.c
index a70edbbbd0..6aff60cd9e 100644
--- a/regex.c
+++ b/regex.c
@@ -185,6 +185,7 @@ static int current_mbctype = MBCTYPE_ASCII;
 
 #ifdef RUBY
 #include "util.h"
+void rb_warn _((char*));
 # define re_warning(x) rb_warn(x)
 #endif