diff --git a/ChangeLog b/ChangeLog
index acc9bf53..3e716975 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-02-07  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Changed the message for FatalException.
+	* src/OptionParser.cc
+	
 2009-02-07  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Documented --bt-external-ip option in man page.  Updated man pages
diff --git a/src/OptionParser.cc b/src/OptionParser.cc
index c2ef8333..f90b63f9 100644
--- a/src/OptionParser.cc
+++ b/src/OptionParser.cc
@@ -141,7 +141,7 @@ void OptionParser::parseArg
       op = findByShortName(c);
     }
     if(op.isNull()) {
-      throw FatalException("Unknown option");
+      throw FatalException("Failed to parse command-line options.");
     }
     out << op->getName() << "=";
     if(optarg) {