diff --git a/libs/widgets/widgets/ardour_spinner.h b/libs/widgets/widgets/ardour_spinner.h
index f9afc66cfa..ab97da33a9 100644
--- a/libs/widgets/widgets/ardour_spinner.h
+++ b/libs/widgets/widgets/ardour_spinner.h
@@ -19,8 +19,6 @@
 #ifndef _WIDGETS_ARDOUR_SPINNER_H_
 #define _WIDGETS_ARDOUR_SPINNER_H_
 
-#include <boost/algorithm/string.hpp>
-
 #include <gtkmm/adjustment.h>
 #include <gtkmm/alignment.h>
 #include <gtkmm/spinbutton.h>