diff --git a/ChangeLog b/ChangeLog
index b7fa2ab802..a5f05e11e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Fri Jan  2 18:41:20 2015  Tanaka Akira  <akr@fsij.org>
+
+	* eval.c (ruby_init): Print ruby_setup() error only in debug mode.
+	  Unsupressable error message is not a good idea.
+	  Note that the message is printed sometimes with following
+	  code (highly timing dependent, though):
+	  pid = spawn("ruby -e ''"); Process.kill(:TERM, pid)
+
 Fri Jan  2 16:18:44 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* test/ruby/test_module.rb: Refactor invalid testcase.
diff --git a/eval.c b/eval.c
index dc5af43928..3fef29a831 100644
--- a/eval.c
+++ b/eval.c
@@ -73,7 +73,8 @@ ruby_init(void)
 {
     int state = ruby_setup();
     if (state) {
-	error_print();
+        if (RTEST(ruby_debug))
+            error_print();
 	exit(EXIT_FAILURE);
     }
 }