diff --git a/ChangeLog b/ChangeLog
index 8e9264944a..5cc31577ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Oct 22 00:20:33 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_str_include): should not treat char as negative value.
+	  [ruby-dev:24558]
+
 Thu Oct 21 19:06:15 2004  GOTOU Yuuzou  <gotoyuzo@notwork.org>
 
 	* lib/webrick/httpresponse.rb (WEBrick::HTTPResponse#send_body_io):
diff --git a/string.c b/string.c
index e2f7fab1e6..bcdd6c3c2c 100644
--- a/string.c
+++ b/string.c
@@ -2422,15 +2422,8 @@ rb_str_include(str, arg)
     long i;
 
     if (FIXNUM_P(arg)) {
-	int c = FIX2INT(arg);
-	long len = RSTRING(str)->len;
-	char *p = RSTRING(str)->ptr;
-
-	for (i=0; i<len; i++) {
-	    if (p[i] == c) {
-		return Qtrue;
-	    }
-	}
+	if (memchr(RSTRING(str)->ptr, FIX2INT(arg), RSTRING(str)->len))
+	    return Qtrue;
 	return Qfalse;
     }