diff --git a/libs/pbd/pbd/abstract_ui.inc.cc b/libs/pbd/pbd/abstract_ui.inc.cc
index f3f735c973..dbc0061060 100644
--- a/libs/pbd/pbd/abstract_ui.inc.cc
+++ b/libs/pbd/pbd/abstract_ui.inc.cc
@@ -21,7 +21,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#include <unistd.h>
 #include <iostream>
 #include <algorithm>