diff --git a/spec/unit/room.spec.js b/spec/unit/room.spec.js
index b98559ecf..726fcda89 100644
--- a/spec/unit/room.spec.js
+++ b/spec/unit/room.spec.js
@@ -1411,4 +1411,27 @@ describe("Room", function() {
             expect(room.getMyMembership()).toEqual("join");
         });
     });
+
+    describe("guessDMUserId", function() {
+        it("should return first hero id",
+        function() {
+            const room = new Room(roomId, null, userA);
+            room.setSummary({'m.heroes': [userB]});
+            expect(room.guessDMUserId()).toEqual(userB);
+        });
+        it("should return first member that isn't self",
+        function() {
+            const room = new Room(roomId, null, userA);
+            room.addLiveEvents([utils.mkMembership({
+                user: userB, mship: "join",
+                room: roomId, event: true,
+            })]);
+            expect(room.guessDMUserId()).toEqual(userB);
+        });
+        it("should return self if only member present",
+        function() {
+            const room = new Room(roomId, null, userA);
+            expect(room.guessDMUserId()).toEqual(userA);
+        });
+    });
 });
diff --git a/src/models/room.js b/src/models/room.js
index b4bd2c111..3e82fa0c0 100644
--- a/src/models/room.js
+++ b/src/models/room.js
@@ -299,27 +299,17 @@ Room.prototype.guessDMUserId = function() {
             return inviterId;
         }
     }
-    const fallbackMember = this.getAvatarFallbackMember();
-    if (fallbackMember) {
-        return fallbackMember.userId;
-    }
-    // now we're getting into sketchy territory,
-    // but we're assuming this room is marked as a DM
-    // so we're going to make a wild-ish guess with whom
-    if (this._summaryHeroes.length) {
+    // remember, we're assuming this room is a DM,
+    // so returning the first member we find should be fine
+    const hasHeroes = Array.isArray(this._summaryHeroes) &&
+        this._summaryHeroes.length;
+    if (hasHeroes) {
         return this._summaryHeroes[0];
     }
     const members = this.currentState.getMembers();
-    const anyMember = members.filter((m) => m.userId !== this.myUserId);
+    const anyMember = members.find((m) => m.userId !== this.myUserId);
     if (anyMember) {
-        return anyMember;
-    }
-    const createEvent = this.currentState.getStateEvents("m.room.create", "");
-    if (createEvent) {
-        const sender = createEvent.getSender();
-        if (sender !== this.myUserId) {
-            return sender;
-        }
+        return anyMember.userId;
     }
     // it really seems like I'm the only user in the room
     // so I probably created a room with just me in it