diff --git a/src/clj/coffi/mem.clj b/src/clj/coffi/mem.clj
index 80be02a..eb8fb7c 100644
--- a/src/clj/coffi/mem.clj
+++ b/src/clj/coffi/mem.clj
@@ -1938,6 +1938,7 @@
                                            (map #(update % 1 keyword))
                                            (map reverse)
                                            (map vec))])]
+        (if (resolve typename) (ns-unmap *ns* typename))
         (register-new-struct-deserialization coffi-typename struct-layout)
         (register-new-struct-serialization   coffi-typename struct-layout)
         `(do