1 files changed, 1 insertions, 1 deletions
diff --git a/re.c b/re.c
index 465e12c8c2..186e11aadd 100644
--- a/re.c
+++ b/re.c
@@ -3141,7 +3141,7 @@ rb_reg_regsub(VALUE str, VALUE src, struct re_registers *regs, VALUE regexp)
     rb_encoding *str_enc = rb_enc_get(str);
     rb_encoding *src_enc = rb_enc_get(src);
     int acompat = rb_enc_asciicompat(str_enc);
-#define ASCGET(s,e,cl) (acompat ? (*cl=1,s[0]) : rb_enc_ascget(s, e, cl, str_enc))
+#define ASCGET(s,e,cl) (acompat ? (*cl=1,ISASCII(s[0])?s[0]:-1) : rb_enc_ascget(s, e, cl, str_enc))
 
     p = s = RSTRING_PTR(str);
     e = s + RSTRING_LEN(str);