diff --git a/Sources/Classes/RSContext.m b/Sources/Classes/RSContext.m
index 84262f4e..97590bb9 100644
--- a/Sources/Classes/RSContext.m
+++ b/Sources/Classes/RSContext.m
@@ -128,6 +128,7 @@ - (void) updateTraits:(RSTraits *)traits {
         if(existingId!=nil && userId!=nil && ![existingId isEqual:userId])
         {
             self->_traits = [[traits dict] mutableCopy];
+            self->_traits[@"anonymousId"] = [self->preferenceManager getAnonymousId];
             [self resetExternalIds];
             return;
         }