diff --git a/owlps-positioning/src/input.cc b/owlps-positioning/src/input.cc
index 4890f71..2196d4b 100644
--- a/owlps-positioning/src/input.cc
+++ b/owlps-positioning/src/input.cc
@@ -57,7 +57,7 @@ void Input::initialise_input_medium()
       InputCSV(Configuration::string_value("input.csv-file")) ;
     }
 
-  if (medium_name == "UDP")
+  else if (medium_name == "UDP")
     {
       if (! Configuration::is_configured("input.udp-port"))
         throw missing_configuration(