diff --git a/COPYING b/COPYING
index cb3c8220..efa6e6cd 100644
--- a/COPYING
+++ b/COPYING
@@ -1,4 +1,4 @@
-Copyright (c) 2009-2012 Alex Shinn
+Copyright (c) 2009-2015 Alex Shinn
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/bignum.c b/bignum.c
index da24dff4..fd0c2b71 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1,5 +1,5 @@
 /*  bignum.c -- bignum support                                */
-/*  Copyright (c) 2009-2013 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #include "chibi/sexp.h"
diff --git a/eval.c b/eval.c
index f2585d56..41fa97ba 100644
--- a/eval.c
+++ b/eval.c
@@ -1,5 +1,5 @@
 /*  eval.c -- evaluator library implementation                */
-/*  Copyright (c) 2009-2013 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #include "chibi/eval.h"
diff --git a/gc.c b/gc.c
index 5f8cf0fc..c8f2ded8 100644
--- a/gc.c
+++ b/gc.c
@@ -1,5 +1,5 @@
 /*  gc.c -- simple mark&sweep garbage collector               */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #if ! SEXP_USE_BOEHM && ! SEXP_USE_MALLOC
diff --git a/include/chibi/bignum.h b/include/chibi/bignum.h
index 1c8402c6..e9386d1a 100644
--- a/include/chibi/bignum.h
+++ b/include/chibi/bignum.h
@@ -1,5 +1,5 @@
 /*  bignum.h -- header for bignum utilities                   */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #ifndef SEXP_BIGNUM_H
diff --git a/include/chibi/eval.h b/include/chibi/eval.h
index e82f8fa2..65be5d5e 100644
--- a/include/chibi/eval.h
+++ b/include/chibi/eval.h
@@ -1,5 +1,5 @@
 /*  eval.h -- headers for eval library                        */
-/*  Copyright (c) 2009-2011 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #ifndef SEXP_EVAL_H
diff --git a/include/chibi/features.h b/include/chibi/features.h
index b145d9aa..1ad3f8c5 100644
--- a/include/chibi/features.h
+++ b/include/chibi/features.h
@@ -1,5 +1,5 @@
 /*  features.h -- general feature configuration               */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 /* uncomment this to disable most features */
diff --git a/include/chibi/sexp.h b/include/chibi/sexp.h
index 78cbde36..119a3a34 100755
--- a/include/chibi/sexp.h
+++ b/include/chibi/sexp.h
@@ -1,5 +1,5 @@
 /*  sexp.h -- header for sexp library                         */
-/*  Copyright (c) 2009-2013 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #ifndef SEXP_H
diff --git a/main.c b/main.c
index 015dd545..1acf3e8a 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,5 @@
 /* main.c -- chibi-scheme command-line app                   */
-/* Copyright (c) 2009-2013 Alex Shinn.  All rights reserved. */
+/* Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /* BSD-style license: http://synthcode.com/license.txt       */
 
 #ifdef EMSCRIPTEN
diff --git a/plan9.c b/plan9.c
index 3123d9a3..f87b1b2f 100644
--- a/plan9.c
+++ b/plan9.c
@@ -1,5 +1,5 @@
 /*  plan9.c -- extended Plan 9 system utils                   */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #include "chibi/eval.h"
diff --git a/sexp.c b/sexp.c
index f3cbb505..aaf65548 100644
--- a/sexp.c
+++ b/sexp.c
@@ -1,5 +1,5 @@
 /*  sexp.c -- standalone sexp library implementation          */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #include "chibi/sexp.h"
diff --git a/simplify.c b/simplify.c
index c30d3a4b..a7b23a71 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1,5 +1,5 @@
 /*  simplify.c -- basic simplification pass                   */
-/*  Copyright (c) 2010-2013 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2010-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #include "chibi/eval.h"
diff --git a/vm.c b/vm.c
index 5fcf6374..3fb0a34c 100644
--- a/vm.c
+++ b/vm.c
@@ -1,5 +1,5 @@
 /*  vm.c -- stack-based virtual machine backend               */
-/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2015 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
 #if SEXP_USE_NATIVE_X86