diff --git a/libs/pbd/cartesian.cc b/libs/pbd/cartesian.cc
index d15f9a3c27..def1786c3e 100644
--- a/libs/pbd/cartesian.cc
+++ b/libs/pbd/cartesian.cc
@@ -16,7 +16,6 @@
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
-#include <iostream>
 #include <math.h>
 
 #include "pbd/cartesian.h"