diff --git a/libraries/AP_Common/TSIndex.h b/libraries/AP_Common/TSIndex.h
index 41821e6d78..6dd88a9216 100644
--- a/libraries/AP_Common/TSIndex.h
+++ b/libraries/AP_Common/TSIndex.h
@@ -98,7 +98,7 @@ private:
     base_type p;
 };
 
-/// This template associates the the base_type array with accessor_type(index).
+/// This template associates the base_type array with accessor_type(index).
 /// So the elements can be accessed using [] only using accessor_type index
 /// _priv_instance is kept public for use in Parameter declaration.
 ///