1 files changed, 2 insertions, 0 deletions
diff --git a/src/op.h b/src/op.h
index dcb0784d..2fc87a71 100644
--- a/src/op.h
+++ b/src/op.h
@@ -45,6 +45,8 @@
 
 namespace ledger {
 
+using namespace boost::placeholders;
+
 class expr_t::op_t : public noncopyable
 {
   friend class expr_t;