diff --git a/owlps-positioner/src/request.cc b/owlps-positioner/src/request.cc
index 67338b2..9ec0dce 100644
--- a/owlps-positioner/src/request.cc
+++ b/owlps-positioner/src/request.cc
@@ -44,6 +44,8 @@
 #include "referencepoint.hh"
 #include "mobile.hh"
 
+#include <sstream>
+
 using namespace std ;
 using std::tr1::unordered_map ;