diff --git a/CHANGES.md b/CHANGES.md
index b402dc0522..76a576099a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -15,6 +15,7 @@ Bugfix 🐛:
  - Account creation: wrongly hints that an email can be used to create an account (#941)
  - Fix crash in the room directory, when public room has no name (#1023)
  - Fix restoring keys backup with passphrase (#526)
+ - Fix joining rooms from directory via federation isn't working. (#808)
 
 Translations 🗣:
  -
diff --git a/vector/src/main/java/im/vector/riotx/features/roomdirectory/PublicRoomsFragment.kt b/vector/src/main/java/im/vector/riotx/features/roomdirectory/PublicRoomsFragment.kt
index 0cb2a7feca..e466c2311f 100644
--- a/vector/src/main/java/im/vector/riotx/features/roomdirectory/PublicRoomsFragment.kt
+++ b/vector/src/main/java/im/vector/riotx/features/roomdirectory/PublicRoomsFragment.kt
@@ -134,7 +134,7 @@ class PublicRoomsFragment @Inject constructor(
 
     override fun onPublicRoomJoin(publicRoom: PublicRoom) {
         Timber.v("PublicRoomJoinClicked: $publicRoom")
-        viewModel.handle(RoomDirectoryAction.JoinRoom(publicRoom.roomId))
+        viewModel.handle(RoomDirectoryAction.JoinRoom(publicRoom.getPrimaryAlias(), publicRoom.roomId))
     }
 
     override fun loadMore() {
diff --git a/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryAction.kt b/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryAction.kt
index 8b32726370..598f26fc3b 100644
--- a/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryAction.kt
+++ b/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryAction.kt
@@ -23,5 +23,5 @@ sealed class RoomDirectoryAction : VectorViewModelAction {
     data class SetRoomDirectoryData(val roomDirectoryData: RoomDirectoryData) : RoomDirectoryAction()
     data class FilterWith(val filter: String) : RoomDirectoryAction()
     object LoadMore : RoomDirectoryAction()
-    data class JoinRoom(val roomId: String) : RoomDirectoryAction()
+    data class JoinRoom(val roomAlias: String?, val roomId: String) : RoomDirectoryAction()
 }
diff --git a/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryViewModel.kt b/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryViewModel.kt
index 9f81e8b076..53661b075a 100644
--- a/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryViewModel.kt
+++ b/vector/src/main/java/im/vector/riotx/features/roomdirectory/RoomDirectoryViewModel.kt
@@ -216,7 +216,7 @@ class RoomDirectoryViewModel @AssistedInject constructor(@Assisted initialState:
             )
         }
 
-        session.joinRoom(action.roomId, callback = object : MatrixCallback<Unit> {
+        session.joinRoom(action.roomAlias ?: action.roomId, callback = object : MatrixCallback<Unit> {
             override fun onSuccess(data: Unit) {
                 // We do not update the joiningRoomsIds here, because, the room is not joined yet regarding the sync data.
                 // Instead, we wait for the room to be joined