diff --git a/owlps-positioning/src/input.cc b/owlps-positioning/src/input.cc
index 4708947..40db41d 100644
--- a/owlps-positioning/src/input.cc
+++ b/owlps-positioning/src/input.cc
@@ -7,6 +7,7 @@
 #include "posexcept.hh"
 #include "stock.hh"
 
+#include <iostream>
 #include <string>
 
 using namespace std ;
diff --git a/owlps-positioning/src/outputtcpsocketevaal.cc b/owlps-positioning/src/outputtcpsocketevaal.cc
index e460510..11fa53e 100644
--- a/owlps-positioning/src/outputtcpsocketevaal.cc
+++ b/owlps-positioning/src/outputtcpsocketevaal.cc
@@ -5,6 +5,7 @@
 #include "stock.hh"
 #include "posexcept.hh"
 
+#include <iostream>
 #include <sstream>
 #include <cstdio> // For perror()
 #include <boost/lexical_cast.hpp>
diff --git a/owlps-positioning/src/positioning.cc b/owlps-positioning/src/positioning.cc
index 0e94cd9..e494fd0 100644
--- a/owlps-positioning/src/positioning.cc
+++ b/owlps-positioning/src/positioning.cc
@@ -11,6 +11,8 @@
 
 #include <owlps.h>
 
+#include <iostream>
+
 using namespace std ;
 
 
diff --git a/owlps-positioning/src/stock.cc b/owlps-positioning/src/stock.cc
index 01e4304..9ee4dab 100644
--- a/owlps-positioning/src/stock.cc
+++ b/owlps-positioning/src/stock.cc
@@ -3,6 +3,8 @@
 #include "posexcept.hh"
 #include "area.hh"
 
+#include <iostream>
+
 using namespace std ;
 using std::tr1::unordered_map ;
 using std::tr1::unordered_set ;