diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 4a0cc470d5..3051a9263f 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -1314,6 +1314,14 @@ export default createReactClass({
             const mxEv = result.context.getEvent();
             const roomId = mxEv.getRoomId();
             const room = this.context.getRoom(roomId);
+            if (!room) {
+                // if we do not have the room in js-sdk stores then hide it as we cannot easily show it
+                // As per the spec, an all rooms search can create this condition,
+                // it happens with Seshat but not Synapse.
+                // It will make the result count not match the displayed count.
+                console.log("Hiding search result from an unknown room", roomId);
+                continue;
+            }
 
             if (!haveTileForEvent(mxEv)) {
                 // XXX: can this ever happen? It will make the result count
@@ -1322,16 +1330,9 @@ export default createReactClass({
             }
 
             if (this.state.searchScope === 'All') {
-                if (roomId != lastRoomId) {
-
-                    // XXX: if we've left the room, we might not know about
-                    // it. We should tell the js sdk to go and find out about
-                    // it. But that's not an issue currently, as synapse only
-                    // returns results for rooms we're joined to.
-                    const roomName = room ? room.name : _t("Unknown room %(roomId)s", { roomId: roomId });
-
+                if (roomId !== lastRoomId) {
                     ret.push(<li key={mxEv.getId() + "-room"}>
-                                 <h2>{ _t("Room") }: { roomName }</h2>
+                                 <h2>{ _t("Room") }: { room.name }</h2>
                              </li>);
                     lastRoomId = roomId;
                 }
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index ed79fc63b7..ba20cf1a29 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -2038,7 +2038,6 @@
     "Search failed": "Search failed",
     "Server may be unavailable, overloaded, or search timed out :(": "Server may be unavailable, overloaded, or search timed out :(",
     "No more results": "No more results",
-    "Unknown room %(roomId)s": "Unknown room %(roomId)s",
     "Room": "Room",
     "Failed to reject invite": "Failed to reject invite",
     "You have %(count)s unread notifications in a prior version of this room.|other": "You have %(count)s unread notifications in a prior version of this room.",