diff --git a/ChangeLog b/ChangeLog
index 1e62df2c99..36526f9c66 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun May 24 01:35:22 2015  Koichi Sasada  <ko1@atdot.net>
+
+	* debug.c (ruby_debug_print_id): use rb_id2name() for fprintf().
+
 Sat May 23 18:38:46 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* man/*.1: updated dates in man pages.
diff --git a/debug.c b/debug.c
index b526ab9523..a5ae6a7467 100644
--- a/debug.c
+++ b/debug.c
@@ -115,7 +115,7 @@ ID
 ruby_debug_print_id(int level, int debug_level, const char *header, ID id)
 {
     if (level < debug_level) {
-	fprintf(stderr, "DBG> %s: %"PRIsVALUE"\n", header, rb_id2str(id));
+	fprintf(stderr, "DBG> %s: %s\n", header, rb_id2name(id));
 	fflush(stderr);
     }
     return id;