Index: b/openvdb/openvdb/tools/VelocityFields.h
===================================================================
--- a/openvdb/openvdb/tools/VelocityFields.h
+++ b/openvdb/openvdb/tools/VelocityFields.h
@@ -25,6 +25,7 @@
 #ifndef OPENVDB_TOOLS_VELOCITY_FIELDS_HAS_BEEN_INCLUDED
 #define OPENVDB_TOOLS_VELOCITY_FIELDS_HAS_BEEN_INCLUDED
 
+#include <boost/static_assert.hpp>
 #include <tbb/parallel_reduce.h>
 #include <openvdb/Platform.h>
 #include <openvdb/openvdb.h>