diff --git a/COPYING b/COPYING
index 9ca75603a..bd61cfb8f 100644
--- a/COPYING
+++ b/COPYING
@@ -13,6 +13,8 @@ WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+(This is the ISC license. <http://opensource.org/licenses/ISC>)
+
 Portions of the code have been contributed by other authors:
 Copyright (c) 2006-2007  Alexander Post
 Copyright (c) 2004-2013  Armin Burgmeier