diff --git a/src/cad.cpp b/src/cad.cpp
index ff22f235f0..970046041e 100644
--- a/src/cad.cpp
+++ b/src/cad.cpp
@@ -25,6 +25,7 @@ void load_cad_geometry_c()
       c.dagmc_ptr = DAGMC;
       c.universe = 0; // set to zero for now
       openmc::cells_c.push_back(c);
+      openmc::cell_dict[c.id] = i;
     }
 
   // initialize surface objects
@@ -38,6 +39,7 @@ void load_cad_geometry_c()
       s->id = DAGMC->id_by_index(2, i);
       s->dagmc_ptr = DAGMC;
       openmc::surfaces_c[i] = s;
+      openmc::surface_dict[s->id] = i;
     }
 
   return;