diff --git a/libs/ardour/ardour/triggerbox.h b/libs/ardour/ardour/triggerbox.h
index 6e57c2095a..8d4097bacf 100644
--- a/libs/ardour/ardour/triggerbox.h
+++ b/libs/ardour/ardour/triggerbox.h
@@ -67,7 +67,7 @@ class SideChain;
 
 typedef uint32_t color_t;
 
-std::string cue_marker_name (int32_t);
+LIBARDOUR_API std::string cue_marker_name (int32_t);
 
 class LIBARDOUR_API Trigger : public PBD::Stateful {
   public: