The purpose of this study was to expand the testing ground of the Interface Hypothesis (Sorace 2005) by investigating the degree to which L2 learners of Bulgarian, with English as their L1, had acquired the pragmatic function of clitic doubling in Bulgarian to mark topical objects. 10 advanced and 14 intermediate L2 speakers of Bulgarian participated in the experiment. The experimental materials included a proficiency test, a grammaticality judgment task to check syntactic knowledge of clitics, and a pragmatic felicity task. Results show that 8 of the advanced and 2 of the intermediate L2 learners have successfully acquired the syntax of clitics as well as the pragmatic meaning of clitic doubling. Their performance on the pragmatic felicity task does not differ significantly from that of the control group of native Bulgarian speakers, which highlights the fact that successful learning at the syntax-pragmatics interface cannot be excluded.