1 files changed, 2 insertions, 0 deletions
diff --git a/value.cc b/value.cc
index 4aa46def..31081ef6 100644
--- a/value.cc
+++ b/value.cc
@@ -707,6 +707,8 @@ void export_value()
     .def(other<amount_t>() / self)
     .def(int() / self)
 
+    .def(- self)
+
     .def(self += self)
     .def(self += other<balance_pair_t>())
     .def(self += other<balance_t>())