diff --git a/src/thread/thread.cpp b/src/thread/thread.cpp
index e8cd5de..f1c1e99 100644
--- a/src/thread/thread.cpp
+++ b/src/thread/thread.cpp
@@ -4,6 +4,8 @@
 #include <fc/log/logger.hpp>
 #include "thread_d.hpp"
 
+#include <iostream>
+
 #if defined(_MSC_VER) && !defined(NDEBUG)
 # include <windows.h>
 const DWORD MS_VC_EXCEPTION=0x406D1388;
diff --git a/tests/thread/parallel_tests.cpp b/tests/thread/parallel_tests.cpp
index ddd04ed..7da4c7b 100644
--- a/tests/thread/parallel_tests.cpp
+++ b/tests/thread/parallel_tests.cpp
@@ -33,6 +33,8 @@
 #include <fc/thread/parallel.hpp>
 #include <fc/time.hpp>
 
+#include <iostream>
+
 struct thread_config {
   thread_config() {
      for( int i = 0; i < boost::unit_test::framework::master_test_suite().argc - 1; ++i )