diff --git a/ChangeLog b/ChangeLog
index f429d3f..b85e87d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-01-29  Naoaki Okazaki  <okazaki at chokkan org>
+
+	* libLBFGS 1.9:
+	- Fixed a mistake in checking the validity of the parameters "ftol" and "wolfe"; this mistake was discovered by Kevin S. Van Horn.
+
+
 2009-07-13  Naoaki Okazaki  <okazaki at chokkan org>
 
 	* libLBFGS 1.8:
diff --git a/configure.in b/configure.in
index 329c27c..82e634d 100644
--- a/configure.in
+++ b/configure.in
@@ -18,7 +18,7 @@ AC_CONFIG_SRCDIR([lib/lbfgs.c])
 dnl ------------------------------------------------------------------
 dnl Initialization for automake
 dnl ------------------------------------------------------------------
-AM_INIT_AUTOMAKE(liblbfgs, 1.8)
+AM_INIT_AUTOMAKE(liblbfgs, 1.9)
 AC_CONFIG_HEADERS(config.h)
 AM_MAINTAINER_MODE
 
diff --git a/doc/footer.html b/doc/footer.html
index 4602a0d..834ec63 100644
--- a/doc/footer.html
+++ b/doc/footer.html
@@ -1,6 +1,6 @@
 <hr/>
 <div>
-Copyright (c) 2002-2009 by Naoaki Okazaki
+Copyright (c) 2002-2010 by Naoaki Okazaki
 <br /><i>$datetime</i>
 </div>
 </body>
diff --git a/include/lbfgs.h b/include/lbfgs.h
index eae5c5c..7aa7b1f 100644
--- a/include/lbfgs.h
+++ b/include/lbfgs.h
@@ -2,7 +2,7 @@
  *      C library of Limited memory BFGS (L-BFGS).
  *
  * Copyright (c) 1990, Jorge Nocedal
- * Copyright (c) 2007,2008,2009,2010 Naoaki Okazaki
+ * Copyright (c) 2007-2010 Naoaki Okazaki
  * All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -584,6 +584,7 @@ Among the various ports of L-BFGS, this library provides several features:
 
 This library is used by:
 - <a href="http://www.chokkan.org/software/crfsuite/">CRFsuite: A fast implementation of Conditional Random Fields (CRFs)</a>
+- <a href="http://www.chokkan.org/software/classias/">Classias: A collection of machine-learning algorithms for classification</a>
 - <a href="http://www.public.iastate.edu/~gdancik/mlegp/">mlegp: an R package for maximum likelihood estimates for Gaussian processes</a>
 - <a href="http://infmath.uibk.ac.at/~matthiasf/imaging2/">imaging2: the imaging2 class library</a>
 - <a href="http://search.cpan.org/~laye/Algorithm-LBFGS-0.16/">Algorithm::LBFGS - Perl extension for L-BFGS</a>
@@ -591,12 +592,15 @@ This library is used by:
 
 @section download Download
 
-- <a href="http://www.chokkan.org/software/dist/liblbfgs-1.8.tar.gz">Source code</a>
+- <a href="http://www.chokkan.org/software/dist/liblbfgs-1.9.tar.gz">Source code</a>
 
 libLBFGS is distributed under the term of the
 <a href="http://opensource.org/licenses/mit-license.php">MIT license</a>.
 
 @section changelog History
+- Version 1.9 (2010-01-29):
+    - Fixed a mistake in checking the validity of the parameters "ftol" and
+      "wolfe"; this was discovered by Kevin S. Van Horn.
 - Version 1.8 (2009-07-13):
     - Accepted the patch submitted by Takashi Imamichi;
       the backtracking method now has three criteria for choosing the step
diff --git a/lib/arithmetic_ansi.h b/lib/arithmetic_ansi.h
index 2c3bf44..fa390da 100644
--- a/lib/arithmetic_ansi.h
+++ b/lib/arithmetic_ansi.h
@@ -1,7 +1,7 @@
 /*
  *      ANSI C implementation of vector operations.
  *
- * Copyright (c) 2007,2008,2009,2010 Naoaki Okazaki
+ * Copyright (c) 2007-2010 Naoaki Okazaki
  * All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/lib/arithmetic_sse_double.h b/lib/arithmetic_sse_double.h
index 6c955ce..ac3be80 100644
--- a/lib/arithmetic_sse_double.h
+++ b/lib/arithmetic_sse_double.h
@@ -1,7 +1,7 @@
 /*
  *      SSE2 implementation of vector oprations (64bit double).
  *
- * Copyright (c) 2007,2008,2009,2010 Naoaki Okazaki
+ * Copyright (c) 2007-2010 Naoaki Okazaki
  * All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/lib/arithmetic_sse_float.h b/lib/arithmetic_sse_float.h
index ef13782..b04bedf 100644
--- a/lib/arithmetic_sse_float.h
+++ b/lib/arithmetic_sse_float.h
@@ -1,7 +1,7 @@
 /*
  *      SSE/SSE3 implementation of vector oprations (32bit float).
  *
- * Copyright (c) 2007,2008,2009,2010 Naoaki Okazaki
+ * Copyright (c) 2007-2010 Naoaki Okazaki
  * All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/lib/lbfgs.c b/lib/lbfgs.c
index 778952f..ec297e3 100644
--- a/lib/lbfgs.c
+++ b/lib/lbfgs.c
@@ -2,7 +2,7 @@
  *      Limited memory BFGS (L-BFGS).
  *
  * Copyright (c) 1990, Jorge Nocedal
- * Copyright (c) 2007,2008,2009,2010 Naoaki Okazaki
+ * Copyright (c) 2007-2010 Naoaki Okazaki
  * All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy