diff --git a/include/openmc/timer.h b/include/openmc/timer.h
index 48b3a9e75..8fbcee46b 100644
--- a/include/openmc/timer.h
+++ b/include/openmc/timer.h
@@ -5,6 +5,27 @@
 
 namespace openmc {
 
+//==============================================================================
+// Global variables
+//==============================================================================
+
+class Timer;
+
+namespace simulation {
+
+extern Timer time_active;
+extern Timer time_bank;
+extern Timer time_bank_sample;
+extern Timer time_bank_sendrecv;
+extern Timer time_finalize;
+extern Timer time_inactive;
+extern Timer time_initialize;
+extern Timer time_tallies;
+extern Timer time_total;
+extern Timer time_transport;
+
+} // namespace simulation
+
 //==============================================================================
 //! Class for measuring time elapsed
 //==============================================================================
@@ -34,21 +55,6 @@ private:
   double elapsed_ {0.0}; //!< elasped time in [s]
 };
 
-//==============================================================================
-// Global variables
-//==============================================================================
-
-extern Timer time_active;
-extern Timer time_bank;
-extern Timer time_bank_sample;
-extern Timer time_bank_sendrecv;
-extern Timer time_finalize;
-extern Timer time_inactive;
-extern Timer time_initialize;
-extern Timer time_tallies;
-extern Timer time_total;
-extern Timer time_transport;
-
 //==============================================================================
 // Non-member functions
 //==============================================================================
diff --git a/src/eigenvalue.cpp b/src/eigenvalue.cpp
index 4d9196ea0..64e0c4e42 100644
--- a/src/eigenvalue.cpp
+++ b/src/eigenvalue.cpp
@@ -67,7 +67,7 @@ void calculate_generation_keff()
 
 void synchronize_bank()
 {
-  time_bank.start();
+  simulation::time_bank.start();
 
   // Get pointers to source/fission bank
   Bank* source_bank;
@@ -131,7 +131,7 @@ void synchronize_bank()
   }
   double p_sample = static_cast<double>(sites_needed) / total;
 
-  time_bank_sample.start();
+  simulation::time_bank_sample.start();
 
   // ==========================================================================
   // SAMPLE N_PARTICLES FROM FISSION BANK AND PLACE IN TEMP_SITES
@@ -204,8 +204,8 @@ void synchronize_bank()
     finish = simulation::work_index[mpi::rank + 1];
   }
 
-  time_bank_sample.stop();
-  time_bank_sendrecv.start();
+  simulation::time_bank_sample.stop();
+  simulation::time_bank_sendrecv.start();
 
 #ifdef OPENMC_MPI
   // ==========================================================================
@@ -303,8 +303,8 @@ void synchronize_bank()
   std::copy(temp_sites.data(), temp_sites.data() + settings::n_particles, source_bank);
 #endif
 
-  time_bank_sendrecv.stop();
-  time_bank.stop();
+  simulation::time_bank_sendrecv.stop();
+  simulation::time_bank.stop();
 }
 
 void calculate_average_keff()
diff --git a/src/initialize.cpp b/src/initialize.cpp
index 2250a6ac8..3a4a3a480 100644
--- a/src/initialize.cpp
+++ b/src/initialize.cpp
@@ -54,8 +54,8 @@ int openmc_init(int argc, char* argv[], const void* intracomm)
   if (err) return err;
 
   // Start total and initialization timer
-  time_total.start();
-  time_initialize.start();
+  simulation::time_total.start();
+  simulation::time_initialize.start();
 
 #ifdef _OPENMP
   // If OMP_SCHEDULE is not set, default to a static schedule
@@ -79,7 +79,7 @@ int openmc_init(int argc, char* argv[], const void* intracomm)
   if (settings::particle_restart_run) settings::run_mode = RUN_MODE_PARTICLE;
 
   // Stop initialization timer
-  time_initialize.stop();
+  simulation::time_initialize.stop();
 
   return 0;
 }
diff --git a/src/simulation.cpp b/src/simulation.cpp
index 55b825a18..b1b657623 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -139,8 +139,8 @@ int openmc_simulation_finalize()
   if (!simulation::initialized) return 0;
 
   // Stop active batch timer and start finalization timer
-  time_active.stop();
-  time_finalize.start();
+  simulation::time_active.stop();
+  simulation::time_finalize.start();
 
 #pragma omp parallel
   {
@@ -166,8 +166,8 @@ int openmc_simulation_finalize()
   }
 
   // Stop timers and show timing statistics
-  time_finalize.stop();
-  time_total.stop();
+  simulation::time_finalize.stop();
+  simulation::time_total.stop();
   if (mpi::master) {
     if (settings::verbosity >= 6) print_runtime();
     if (settings::verbosity >= 4) print_results();
@@ -200,7 +200,7 @@ int openmc_next_batch(int* status)
     initialize_generation();
 
     // Start timer for transport
-    time_transport.start();
+    simulation::time_transport.start();
 
     // ====================================================================
     // LOOP OVER PARTICLES
@@ -218,7 +218,7 @@ int openmc_next_batch(int* status)
     }
 
     // Accumulate time for transport
-    time_transport.stop();
+    simulation::time_transport.stop();
 
     finalize_generation();
   }
@@ -305,10 +305,10 @@ void initialize_batch()
 
   // Manage active/inactive timers and activate tallies if necessary.
   if (first_inactive) {
-    time_inactive.start();
+    simulation::time_inactive.start();
   } else if (first_active) {
-    time_inactive.stop();
-    time_active.start();
+    simulation::time_inactive.stop();
+    simulation::time_active.start();
     for (int i = 1; i <= n_tallies; ++i) {
       // TODO: change one-based index
       openmc_tally_set_active(i, true);
@@ -327,9 +327,9 @@ void initialize_batch()
 void finalize_batch()
 {
   // Reduce tallies onto master process and accumulate
-  time_tallies.start();
+  simulation::time_tallies.start();
   accumulate_tallies();
-  time_tallies.stop();
+  simulation::time_tallies.stop();
 
   // Reset global tally results
   if (simulation::current_batch <= settings::n_inactive) {
diff --git a/src/timer.cpp b/src/timer.cpp
index f1c211446..7dab802b0 100644
--- a/src/timer.cpp
+++ b/src/timer.cpp
@@ -2,6 +2,25 @@
 
 namespace openmc {
 
+//==============================================================================
+// Global variables
+//==============================================================================
+
+namespace simulation {
+
+Timer time_active;
+Timer time_bank;
+Timer time_bank_sample;
+Timer time_bank_sendrecv;
+Timer time_finalize;
+Timer time_inactive;
+Timer time_initialize;
+Timer time_tallies;
+Timer time_total;
+Timer time_transport;
+
+} // namespace simulation
+
 //==============================================================================
 // Timer implementation
 //==============================================================================
@@ -34,35 +53,20 @@ double Timer::elapsed()
   }
 }
 
-//==============================================================================
-// Global variables
-//==============================================================================
-
-Timer time_active;
-Timer time_bank;
-Timer time_bank_sample;
-Timer time_bank_sendrecv;
-Timer time_finalize;
-Timer time_inactive;
-Timer time_initialize;
-Timer time_tallies;
-Timer time_total;
-Timer time_transport;
-
 //==============================================================================
 // Fortran compatibility
 //==============================================================================
 
-extern "C" double time_active_elapsed() { return time_active.elapsed(); }
-extern "C" double time_bank_elapsed() { return time_bank.elapsed(); }
-extern "C" double time_bank_sample_elapsed() { return time_bank_sample.elapsed(); }
-extern "C" double time_bank_sendrecv_elapsed() { return time_bank_sendrecv.elapsed(); }
-extern "C" double time_finalize_elapsed() { return time_finalize.elapsed(); }
-extern "C" double time_inactive_elapsed() { return time_inactive.elapsed(); }
-extern "C" double time_initialize_elapsed() { return time_initialize.elapsed(); }
-extern "C" double time_tallies_elapsed() { return time_tallies.elapsed(); }
-extern "C" double time_total_elapsed() { return time_total.elapsed(); }
-extern "C" double time_transport_elapsed() { return time_transport.elapsed(); }
+extern "C" double time_active_elapsed() { return simulation::time_active.elapsed(); }
+extern "C" double time_bank_elapsed() { return simulation::time_bank.elapsed(); }
+extern "C" double time_bank_sample_elapsed() { return simulation::time_bank_sample.elapsed(); }
+extern "C" double time_bank_sendrecv_elapsed() { return simulation::time_bank_sendrecv.elapsed(); }
+extern "C" double time_finalize_elapsed() { return simulation::time_finalize.elapsed(); }
+extern "C" double time_inactive_elapsed() { return simulation::time_inactive.elapsed(); }
+extern "C" double time_initialize_elapsed() { return simulation::time_initialize.elapsed(); }
+extern "C" double time_tallies_elapsed() { return simulation::time_tallies.elapsed(); }
+extern "C" double time_total_elapsed() { return simulation::time_total.elapsed(); }
+extern "C" double time_transport_elapsed() { return simulation::time_transport.elapsed(); }
 
 //==============================================================================
 // Non-member functions
@@ -70,16 +74,16 @@ extern "C" double time_transport_elapsed() { return time_transport.elapsed(); }
 
 void reset_timers()
 {
-  time_active.reset();
-  time_bank.reset();
-  time_bank_sample.reset();
-  time_bank_sendrecv.reset();
-  time_finalize.reset();
-  time_inactive.reset();
-  time_initialize.reset();
-  time_tallies.reset();
-  time_total.reset();
-  time_transport.reset();
+  simulation::time_active.reset();
+  simulation::time_bank.reset();
+  simulation::time_bank_sample.reset();
+  simulation::time_bank_sendrecv.reset();
+  simulation::time_finalize.reset();
+  simulation::time_inactive.reset();
+  simulation::time_initialize.reset();
+  simulation::time_tallies.reset();
+  simulation::time_total.reset();
+  simulation::time_transport.reset();
 }
 
 } // namespace openmc