diff --git a/fpm/src/fTimers.cpp b/fpm/src/fTimers.cpp
index f2d6838817a5a7c1511ad5279191fd2432871ff4..9a8f5f8ab6fd070f56c1650b8918d5db41eb8322 100644
--- a/fpm/src/fTimers.cpp
+++ b/fpm/src/fTimers.cpp
@@ -87,7 +87,7 @@ void Timers::write(std::ostream &out) const
         << std::setw(15) << std::right << "CPU (s)"
         << std::endl;
 
-    for (auto const tm : timers)
+    for (auto const &tm : timers)
     {
         out << std::setw(20) << std::left << tm.first
             << std::setw(15) << std::right << tm.second.getWall()
diff --git a/fpm/src/fTimers.h b/fpm/src/fTimers.h
index 510df454d53cc0a50dd3936c128ab695d3d7aa7b..e08840b545098430c1267a96b62bb6138474da09 100644
--- a/fpm/src/fTimers.h
+++ b/fpm/src/fTimers.h
@@ -21,6 +21,8 @@
 #include "wObject.h"
 #include <map>
 #include <chrono>
+#include <ctime>
+#include <string>
 
 namespace fpm
 {