diff --git a/ChangeLog b/ChangeLog
index cc3fff3ac5..92d27bc3d9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Wed Dec 24 20:59:12 2008  Koichi Sasada  <ko1@atdot.net>
+
+	* error.c (exc_equal): == method should not raise Exception.
+	  [ruby-dev:37519]
+
+	* sample/test.rb: fix test.
+
 Wed Dec 24 20:33:45 2008  Koichi Sasada  <ko1@atdot.net>
 
 	* vm_insnhelper.c (vm_call_method): use class of method defined
diff --git a/error.c b/error.c
index 90a7d417e5..b6ab8c4959 100644
--- a/error.c
+++ b/error.c
@@ -559,14 +559,25 @@ exc_equal(VALUE exc, VALUE obj)
 
     if (exc == obj) return Qtrue;
     CONST_ID(id_mesg, "mesg");
+
     if (rb_obj_class(exc) != rb_obj_class(obj)) {
-	mesg = rb_funcall(obj, rb_intern("message"), 0, 0);
-	backtrace = rb_funcall(obj, rb_intern("backtrace"), 0, 0);
+	ID id_message, id_backtrace;
+	CONST_ID(id_message, "message");
+	CONST_ID(id_backtrace, "backtrace");
+
+	if (rb_respond_to(obj, id_message) && rb_respond_to(obj, id_backtrace)) {
+	    mesg = rb_funcall(obj, id_message, 0, 0);
+	    backtrace = rb_funcall(obj, id_backtrace, 0, 0);
+	}
+	else {
+	    return Qfalse;
+	}
     }
     else {
 	mesg = rb_attr_get(obj, id_mesg);
 	backtrace = exc_backtrace(obj);
     }
+
     if (!rb_equal(rb_attr_get(exc, id_mesg), mesg))
 	return Qfalse;
     if (!rb_equal(exc_backtrace(exc), backtrace))
diff --git a/sample/test.rb b/sample/test.rb
index 5448a40ba5..21656885f6 100644
--- a/sample/test.rb
+++ b/sample/test.rb
@@ -661,9 +661,11 @@ begin
   end
   test_ok(false)
 rescue => e
-  test_ok(true) if $! == e
+  test_ok($! == e)
+  test_ok(e.message == $string)
+  test_ok(e != $string)
 end
-  
+
 # exception in ensure clause
 begin
   begin