diff --git a/include/openmc/finalize.h b/include/openmc/finalize.h
index 58cf75606..5a8238841 100644
--- a/include/openmc/finalize.h
+++ b/include/openmc/finalize.h
@@ -1,6 +1,10 @@
 #ifndef OPENMC_FINALIZE_H
 #define OPENMC_FINALIZE_H
 
+namespace openmc {
+
 extern "C" void openmc_free_bank();
 
+} // namespace openmc
+
 #endif // OPENMC_FINALIZE_H
diff --git a/src/finalize.cpp b/src/finalize.cpp
index 3b4f26764..7f07ddac0 100644
--- a/src/finalize.cpp
+++ b/src/finalize.cpp
@@ -2,9 +2,13 @@
 
 #include "openmc/message_passing.h"
 
+namespace openmc {
+
 void openmc_free_bank()
 {
 #ifdef OPENMC_MPI
-  MPI_Type_free(&openmc::mpi::bank);
+  MPI_Type_free(&mpi::bank);
 #endif
 }
+
+} // namespace openmc