diff --git a/knockoutwhistweb/app/logic/user/SessionManager.scala b/knockoutwhistweb/app/logic/user/SessionManager.scala
index c573b23..aad7472 100644
--- a/knockoutwhistweb/app/logic/user/SessionManager.scala
+++ b/knockoutwhistweb/app/logic/user/SessionManager.scala
@@ -1,7 +1,10 @@
 package logic.user
 
+import com.google.inject.ImplementedBy
+import logic.user.impl.BaseSessionManager
 import model.users.User
 
+@ImplementedBy(classOf[BaseSessionManager])
 trait SessionManager {
   
   def createSession(user: User): String
diff --git a/knockoutwhistweb/app/logic/user/UserManager.scala b/knockoutwhistweb/app/logic/user/UserManager.scala
index 69e4481..b6a4f47 100644
--- a/knockoutwhistweb/app/logic/user/UserManager.scala
+++ b/knockoutwhistweb/app/logic/user/UserManager.scala
@@ -1,10 +1,15 @@
 package logic.user
 
+import com.google.inject.ImplementedBy
+import logic.user.impl.StubUserManager
+import model.users.User
+
+@ImplementedBy(classOf[StubUserManager])
 trait UserManager {
 
   def addUser(name: String, password: String): Boolean
-  def authenticate(name: String, password: String): Boolean
-  def userExists(name: String): Boolean
+  def authenticate(name: String, password: String): Option[User]
+  def userExists(name: String): Option[User]
   def removeUser(name: String): Boolean
 
 }