diff --git a/owlps-positioning/src/posutil.hh b/owlps-positioning/src/posutil.hh
index 22d1cbd..8e56ebb 100644
--- a/owlps-positioning/src/posutil.hh
+++ b/owlps-positioning/src/posutil.hh
@@ -4,6 +4,7 @@
 class Measurement ;
 
 #include <boost/tr1/unordered_map.hpp>
+#include <boost/algorithm/string/case_conv.hpp>
 
 /// Utilitary class
 class PosUtil
@@ -29,6 +30,34 @@ public:
   /// Converts a Wi-Fi channel to the corresponding frequency in Hz
   static unsigned long wifi_channel_to_hz(const unsigned long &channel) ;
   //@}
+
+  /** @name Strings */
+  //@{
+  static void to_upper(std::string &str) ;
+  static void assert_uppercase(const std::string &str) ;
+  //@}
 } ;
 
+
+
+/* *** Strings *** */
+
+
+inline void PosUtil::to_upper(std::string &str)
+{
+  boost::to_upper(str) ;
+}
+
+
+inline void PosUtil::assert_uppercase(const std::string &str)
+{
+#ifndef NDEBUG
+  std::string str_up(str) ;
+  to_upper(str_up) ;
+  assert(str_up == str) ;
+#endif // NDEBUG
+}
+
+
+
 #endif // _OWLPS_POSITIONING_POSUTIL_HH_