diff --git a/LICENSE b/LICENSE
index 3855a8e..1d66b96 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2014 - 2016, Přemysl Janouch <p.janouch@gmail.com>
+Copyright (c) 2014 - 2017, Přemysl Janouch <p.janouch@gmail.com>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above
diff --git a/liberty.c b/liberty.c
index da95482..9848c1b 100644
--- a/liberty.c
+++ b/liberty.c
@@ -2639,7 +2639,7 @@ tolower_ascii (int c)
 static int
 toupper_ascii (int c)
 {
-	return c >= 'A' && c <= 'Z' ? c : c - ('a' - 'A');
+	return c >= 'a' && c <= 'z' ? c - ('a' - 'A') : c;
 }
 
 TRIVIAL_STRXFRM (tolower_ascii_strxfrm, tolower_ascii)