diff --git a/ChangeLog b/ChangeLog
index aa5519a616..9aa50b1fd1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Tue Sep 15 03:00:35 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* string.c (rb_str_lstrip_bang): use ascii_isspace().  [ruby-dev:39322]
+
+	* string.c (rb_str_rstrip_bang): ditto.
+
+	* string.c (rb_str_split_m): ditto.
+
 Mon Sep 14 16:39:14 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* debug.c, parse.y: fixed types.
diff --git a/string.c b/string.c
index 9aea029fe5..4a383c2e6f 100644
--- a/string.c
+++ b/string.c
@@ -5669,7 +5669,7 @@ rb_str_split_m(int argc, VALUE *argv, VALUE str)
 		c = rb_enc_codepoint_len(ptr, eptr, &n, enc);
 		ptr += n;
 		if (skip) {
-		    if (rb_enc_isspace(c, enc)) {
+		    if (ascii_isspace(c)) {
 			beg = ptr - bptr;
 		    }
 		    else {
@@ -5678,7 +5678,7 @@ rb_str_split_m(int argc, VALUE *argv, VALUE str)
 			if (!NIL_P(limit) && lim <= i) break;
 		    }
 		}
-		else if (rb_enc_isspace(c, enc)) {
+		else if (ascii_isspace(c)) {
 		    rb_ary_push(result, rb_str_subseq(str, beg, end-beg));
 		    skip = 1;
 		    beg = ptr - bptr;
@@ -6320,7 +6320,7 @@ rb_str_lstrip_bang(VALUE str)
 	int n;
 	unsigned int cc = rb_enc_codepoint_len(s, e, &n, enc);
 
-	if (!rb_enc_isspace(cc, enc)) break;
+	if (!ascii_isspace(cc)) break;
 	s += n;
     }
 
@@ -6382,14 +6382,14 @@ rb_str_rstrip_bang(VALUE str)
     /* remove trailing spaces or '\0's */
     if (single_byte_optimizable(str)) {
 	unsigned char c;
-	while (s < t && ((c = *(t-1)) == '\0' || rb_enc_isspace(c, enc))) t--;
+	while (s < t && ((c = *(t-1)) == '\0' || ascii_isspace(c))) t--;
     }
     else {
 	char *tp;
 
         while ((tp = rb_enc_prev_char(s, t, e, enc)) != NULL) {
 	    unsigned int c = rb_enc_codepoint(tp, e, enc);
-	    if (c && !rb_enc_isspace(c, enc)) break;
+	    if (c && !ascii_isspace(c)) break;
 	    t = tp;
 	}
     }
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index 36968cae3f..36a8f67442 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -1139,8 +1139,6 @@ class TestString < Test::Unit::TestCase
   def test_strip
     assert_equal(S("x"), S("      x        ").strip)
     assert_equal(S("x"), S(" \n\r\t     x  \t\r\n\n      ").strip)
-    assert_equal(S(""), S("\xa0".force_encoding("iso-8859-1")).strip)
-    assert_equal(S("a"), S("a\xa0".force_encoding("iso-8859-1")).strip)
   end
 
   def test_strip!