diff --git a/ChangeLog b/ChangeLog
index 1543907c3f..563199b1ab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sat Nov 10 23:50:31 2007  Tanaka Akira  <akr@fsij.org>
+
+	* string.c (tr_trans): cast to unsigned char after dereference
+	  a pointer to a char to avoid SEGV with "\377".tr("a", "b").
+	  on FreeBSD/amd64.
+
 Sat Nov 10 23:08:53 2007  Tanaka Akira  <akr@fsij.org>
 
 	* configure.in, common.mk, Makefile.in: don't generate
diff --git a/string.c b/string.c
index 07ccf897c7..4ff50a776d 100644
--- a/string.c
+++ b/string.c
@@ -3475,7 +3475,7 @@ tr_trans(VALUE str, VALUE src, VALUE repl, int sflag)
     }
     else if (rb_enc_mbmaxlen(enc) == 1) {
 	while (s < send) {
-	    c = *s;
+	    c = (unsigned char)*s;
 	    if (trans[c] >= 0) {
 		if (!cflag) {
 		    c = FIX2INT(trans[c]);