2 files changed, 7 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index ec528081a8..8526a7152c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Apr 28 16:52:05 2016  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* re.c (rb_reg_prepare_enc): use rb_enc_asciicompat(enc) instead of
+	  rb_enc_str_asciicompat_p(str) to avoid useless rb_enc_get(str) call.
+
 Thu Apr 28 16:33:41 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/optparse.rb: [DOC] fix example code.  base on the code by
diff --git a/re.c b/re.c
index e8c42b7705..b515b9f2f8 100644
--- a/re.c
+++ b/re.c
@@ -1384,7 +1384,7 @@ rb_reg_prepare_enc(VALUE re, VALUE str, int warn)
 
     rb_reg_check(re);
     enc = rb_enc_get(str);
-    if (!rb_enc_str_asciicompat_p(str)) {
+    if (!rb_enc_asciicompat(enc)) {
         if (RREGEXP_PTR(re)->enc != enc) {
 	    reg_enc_error(re, str);
 	}
@@ -3408,7 +3408,7 @@ rb_reg_s_union(VALUE self, VALUE args0)
                 rb_encoding *enc;
                 StringValue(e);
                 enc = rb_enc_get(e);
-                if (!rb_enc_str_asciicompat_p(e)) {
+                if (!rb_enc_asciicompat(enc)) {
                     if (!has_ascii_incompat)
                         has_ascii_incompat = enc;
                     else if (has_ascii_incompat != enc)