diff --git a/src/AmbiguousInterface.php b/src/AmbiguousInterface.php
new file mode 100644
index 0000000..4dd6805
--- /dev/null
+++ b/src/AmbiguousInterface.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Ratp;
+
+interface AmbiguousInterface
+{
+    public function getAmbiguityMessage();
+
+    public function setAmbiguityMessage($ambiguityMessage);
+}
diff --git a/src/WrDirections.php b/src/WrDirections.php
index 08525ea..e528d2e 100644
--- a/src/WrDirections.php
+++ b/src/WrDirections.php
@@ -1,9 +1,9 @@
 <?php
+
 namespace Ratp;
 
-class WrDirections
+class WrDirections implements AmbiguousInterface
 {
-
     /**
      * @var string $ambiguityMessage
      */
diff --git a/src/WrItineraries.php b/src/WrItineraries.php
index 75135cb..bfe00af 100644
--- a/src/WrItineraries.php
+++ b/src/WrItineraries.php
@@ -1,7 +1,8 @@
 <?php
+
 namespace Ratp;
 
-class WrItineraries
+class WrItineraries implements AmbiguousInterface
 {
     /**
      * @var string $ambiguityMessage
diff --git a/src/WrMission.php b/src/WrMission.php
index 243914b..f8c5948 100644
--- a/src/WrMission.php
+++ b/src/WrMission.php
@@ -1,7 +1,8 @@
 <?php
+
 namespace Ratp;
 
-class WrMission
+class WrMission implements AmbiguousInterface
 {
     /**
      * @var string $ambiguityMessage
diff --git a/src/WrMissions.php b/src/WrMissions.php
index 3e3b9c3..1cb20f9 100644
--- a/src/WrMissions.php
+++ b/src/WrMissions.php
@@ -1,9 +1,10 @@
 <?php
+
 namespace Ratp;
 
 use Mission;
 
-class WrMissions
+class WrMissions implements AmbiguousInterface
 {
     /**
      * @var string $ambiguityMessage
diff --git a/src/WrStations.php b/src/WrStations.php
index 9cf755a..518bba9 100644
--- a/src/WrStations.php
+++ b/src/WrStations.php
@@ -1,9 +1,9 @@
 <?php
+
 namespace Ratp;
 
-class WrStations
+class WrStations implements AmbiguousInterface
 {
-
     /**
      * @var string $ambiguityMessage
      */