diff --git a/build/shared/examples/Sensors/Knock/Knock.pde b/build/shared/examples/Sensors/Knock/Knock.pde
index 05e4632e9..bdb557e2f 100644
--- a/build/shared/examples/Sensors/Knock/Knock.pde
+++ b/build/shared/examples/Sensors/Knock/Knock.pde
@@ -16,6 +16,8 @@
    by David Cuartielles <http://www.0j0.org>
    modified 30 Jun 2009
    by Tom Igoe
+   
+   This example code is in the public domain.
 
  */