diff --git a/libs/temporal/tempo.cc b/libs/temporal/tempo.cc
index 244e1f0b27..8cb99d23d7 100644
--- a/libs/temporal/tempo.cc
+++ b/libs/temporal/tempo.cc
@@ -653,6 +653,7 @@ TempoMap::operator= (TempoMap const & other)
 {
 	_time_domain = other.time_domain();
 	copy_points (other);
+	return *this;
 }
 
 void