diff --git a/amount.cc b/amount.cc
index 087a9bc5..9aebec26 100644
--- a/amount.cc
+++ b/amount.cc
@@ -4,6 +4,7 @@
 #include <list>
 #include <sstream>
 #include <cstdlib>
+#include <memory>
 
 #include <gmp.h>