Pakistani English (PakE) does not differentiate between [v] and [w]. This study focuses on pronunciation and comprehension of such adult Pakistani speakers of English who, after learning PakE in Pakistan, immersed with native British English (BrE) speakers in England. The study aims to determine if native BrE input has any positive effect on pronunciation of the adult speakers who have already acquired English in a non-native environment like Pakistan. Comprehension and production experiments were arranged with 30 adult Pakistani speakers of English who, after acquiring PakE migrated to England and at the time of experiment, were receiving input from native speakers of English for 5-6 hours daily. The results show that they still confuse [v] and [w]. These results demonstrate that if adult L2 speakers first learn an L2 dialect, which does not differentiate between two consonants, even long immersion with native speakers in later life cannot bring any improvement in their pronunciation of such problematic consonants.