diff --git a/libs/temporal/temporal/tempo.h b/libs/temporal/temporal/tempo.h
index 44cf2c5df7..a96565e6c2 100644
--- a/libs/temporal/temporal/tempo.h
+++ b/libs/temporal/temporal/tempo.h
@@ -733,7 +733,7 @@ class /*LIBTEMPORAL_API*/ TempoMap : public PBD::StatefulDestructible
 	LIBTEMPORAL_API void set_time_domain (TimeDomain td);
 	LIBTEMPORAL_API int set_state (XMLNode const&, int version);
 
-	void twist_tempi (TempoPoint* ts, timepos_t const & start, timepos_t const & end);
+	LIBTEMPORAL_API void twist_tempi (TempoPoint* ts, timepos_t const & start, timepos_t const & end);
 
 	/* END OF MODIFYING METHODS */