diff --git a/src/finalize.cpp b/src/finalize.cpp
index 120903f3fe..7c39a7c198 100644
--- a/src/finalize.cpp
+++ b/src/finalize.cpp
@@ -127,7 +127,9 @@ int openmc_finalize()
 
   // Free all MPI types
 #ifdef OPENMC_MPI
-  MPI_Type_free(&mpi::bank);
+  int init_called;
+  MPI_Initialized(&init_called);
+  if (init_called) MPI_Type_free(&mpi::bank);
 #endif
 
   return 0;
diff --git a/src/message_passing.cpp b/src/message_passing.cpp
index 278bf924d3..aea17f9f49 100644
--- a/src/message_passing.cpp
+++ b/src/message_passing.cpp
@@ -8,8 +8,8 @@ int n_procs {1};
 bool master {true};
 
 #ifdef OPENMC_MPI
-MPI_Comm intracomm;
-MPI_Datatype bank;
+MPI_Comm intracomm {MPI_COMM_NULL};
+MPI_Datatype bank {MPI_DATATYPE_NULL};
 #endif
 
 extern "C" bool openmc_master() { return mpi::master; }