diff --git a/libs/pbd3/convert.cc b/libs/pbd3/convert.cc
index 6b24f69c40..0b3d3e1db9 100644
--- a/libs/pbd3/convert.cc
+++ b/libs/pbd3/convert.cc
@@ -18,6 +18,7 @@
 */
 
 #include <cmath>
+#include <stdint.h>
 
 #include "pbd/convert.h"