diff --git a/owlps-positioning/src/outputtcpsocketevaal.cc b/owlps-positioning/src/outputtcpsocketevaal.cc
index 8005a43..e460510 100644
--- a/owlps-positioning/src/outputtcpsocketevaal.cc
+++ b/owlps-positioning/src/outputtcpsocketevaal.cc
@@ -1,10 +1,13 @@
 #include "outputtcpsocketevaal.hh"
 #include "request.hh"
 #include "resultlist.hh"
+#include "area.hh"
+#include "stock.hh"
 #include "posexcept.hh"
 
 #include <sstream>
 #include <cstdio> // For perror()
+#include <boost/lexical_cast.hpp>
 
 using namespace std ;
 
@@ -91,11 +94,22 @@ bool OutputTCPSocketEvAAL::close_socket()
 }
 
 
+/**
+ * @param results Must contain only one element, since the EvAAL format
+ * accepts only one algorithm result.
+ */
+void OutputTCPSocketEvAAL::write(const ResultList &results)
+{
+  assert(results.get_results().size() == 1) ;
+  write(results.get_results()[0]) ;
+}
+
+
 void OutputTCPSocketEvAAL::write(const Result &result)
 {
   const Point3D &position = result.get_position() ;
   Timestamp request_time = result.get_request()->get_time_sent() ;
-  int area_of_interest = 0 ; // FIXME
+  int area_of_interest = area_of_interest_number(position) ;
 
   ostringstream str ;
   str
@@ -110,14 +124,27 @@ void OutputTCPSocketEvAAL::write(const Result &result)
 }
 
 
-/**
- * @param results Must contain only one element, since the EvAAL format
- * accepts only one algorithm result.
- */
-void OutputTCPSocketEvAAL::write(const ResultList &results)
+int OutputTCPSocketEvAAL::
+area_of_interest_number(const Point3D &position) const
 {
-  assert(results.get_results().size() == 1) ;
-  write(results.get_results()[0]) ;
+  const Area *area = Stock::in_which_area_is(position) ;
+  if (area == NULL)
+    return 0 ;
+
+  int aoi_number = 0 ;
+  try
+    {
+      aoi_number = boost::lexical_cast<int>(area->get_name()) ;
+    }
+  catch (boost::bad_lexical_cast &e)
+    {
+      cerr
+          << "Cannot convert the area of interest's name (« "
+          << area->get_name() << " ») into an integer value: "
+          << e.what() << '\n' ;
+    }
+
+  return aoi_number ;
 }
 
 
diff --git a/owlps-positioning/src/outputtcpsocketevaal.hh b/owlps-positioning/src/outputtcpsocketevaal.hh
index b355b59..791761a 100644
--- a/owlps-positioning/src/outputtcpsocketevaal.hh
+++ b/owlps-positioning/src/outputtcpsocketevaal.hh
@@ -1,6 +1,8 @@
 #ifndef _OWLPS_POSITIONING_OUTPUTTCPSOCKETEVAAL_HH_
 #define _OWLPS_POSITIONING_OUTPUTTCPSOCKETEVAAL_HH_
 
+class Point3D ;
+
 #include "outputmedium.hh"
 
 #include <string>
@@ -39,8 +41,10 @@ public:
 
   /** @name Operations */
   //@{
-  void write(const Result &result) ;
   void write(const ResultList &results) ;
+  void write(const Result &result) ;
+  /// Get the area of interest number from the position
+  int area_of_interest_number(const Point3D &position) const ;
   /// Closes the socket
   bool close_socket(void) ;
   //@}