diff --git a/src/dagmc.cpp b/src/dagmc.cpp
index b5f327d06f..e6ccee24d5 100644
--- a/src/dagmc.cpp
+++ b/src/dagmc.cpp
@@ -14,8 +14,12 @@
 
 namespace openmc {
 
+namespace model {
+
 moab::DagMC* DAG;
 
+} // namespace model
+
 void load_dagmc_geometry()
 {
   if (!model::DAG) {
@@ -96,7 +100,7 @@ void load_dagmc_geometry()
 
   // initialize surface objects
   int n_surfaces = model::DAG->num_entities(2);
-  surfaces.resize(n_surfaces);
+  model::surfaces.resize(n_surfaces);
 
   for (int i = 0; i < n_surfaces; i++) {
     moab::EntityHandle surf_handle = model::DAG->entity_by_index(2, i+1);