diff --git a/test/io/time_point_output.cpp b/test/io/time_point_output.cpp
index a1ecd8c..8aa631a 100644
--- a/test/io/time_point_output.cpp
+++ b/test/io/time_point_output.cpp
@@ -10,6 +10,7 @@
 #include <boost/chrono/process_cpu_clocks.hpp>
 #include <locale>
 #include <ctime>
+#include <cstdio>
 
 template <typename Clock, typename D>
 void test_good_prefix(const char* str, D d)
diff --git a/test/test_7868.cpp b/test/test_7868.cpp
index 6d77235..dfe9746 100644
--- a/test/test_7868.cpp
+++ b/test/test_7868.cpp
@@ -26,10 +26,16 @@ int main()
       // does not change anything: strm2<<time_fmt(boost::chrono::timezone::utc);
       boost::chrono::system_clock::time_point atnow2;
       strm<<atnow<<std::endl;
+      time_t t = boost::chrono::system_clock::to_time_t(atnow);
+      std::cout << "A:" << std::endl;
+      puts(ctime(&t));
+      std::cout << "A:" << std::endl;
       std::cout << "A:" << strm.str()<< std::endl;
+      std::cout << "A:" << atnow.time_since_epoch().count() << std::endl;
       strm>>atnow2;
       strm2<<atnow2<<std::endl;
       std::cout << "B:" << strm2.str()<< std::endl;
+      std::cout << "B:" << atnow2.time_since_epoch().count()<< std::endl;
       BOOST_TEST_EQ(atnow.time_since_epoch().count(), atnow2.time_since_epoch().count());
 
       // 1 sec wrong: