diff --git a/gtsam/nonlinear/ISAM2.cpp b/gtsam/nonlinear/ISAM2.cpp
index 0e093003f..7cda2b901 100644
--- a/gtsam/nonlinear/ISAM2.cpp
+++ b/gtsam/nonlinear/ISAM2.cpp
@@ -19,6 +19,7 @@
 #include <boost/assign/std/list.hpp> // for operator +=
 using namespace boost::assign;
 #include <boost/range/adaptors.hpp>
+#include <boost/range/algorithm/copy.hpp>
 #include <boost/algorithm/string.hpp>
 namespace br { using namespace boost::range; using namespace boost::adaptors; }