diff --git a/matrixConsole/API/ContactManager.m b/matrixConsole/API/ContactManager.m
index 7b4e9a716..ab466cdad 100644
--- a/matrixConsole/API/ContactManager.m
+++ b/matrixConsole/API/ContactManager.m
@@ -226,7 +226,7 @@ static ContactManager* sharedContactManager = nil;
     
     for(MXUser* user in users) {
         
-        if ([knownUserIDs indexOfObject:user.userId] == NSNotFound) {
+        if (!knownUserIDs || [knownUserIDs indexOfObject:user.userId] == NSNotFound) {
             NSString* dummyContactID = [NSString stringWithFormat:@"%lu", (unsigned long)user.userId.hash];
             
             // with the current API, there is no way to get the email from the matrxID