diff --git a/common/trans.c b/common/trans.c
index 55d2a638..7a98986c 100644
--- a/common/trans.c
+++ b/common/trans.c
@@ -120,6 +120,12 @@ trans_delete(struct trans *self)
         return;
     }
 
+    /* Call the user-specified destructor if one exists */
+    if (self->extra_destructor != NULL)
+    {
+        self->extra_destructor(self);
+    }
+
     free_stream(self->in_s);
     free_stream(self->out_s);
 
diff --git a/common/trans.h b/common/trans.h
index 876e8b9b..9810cefd 100644
--- a/common/trans.h
+++ b/common/trans.h
@@ -108,6 +108,9 @@ struct trans
     char port[256];
     int no_stream_init_on_data_in;
     int extra_flags; /* user defined */
+    void *extra_data; /* user defined */
+    void (*extra_destructor)(struct trans *); /* user defined */
+
     struct ssl_tls *tls;
     const char *ssl_protocol; /* e.g. TLSv1, TLSv1.1, TLSv1.2, unknown */
     const char *cipher_name;  /* e.g. AES256-GCM-SHA384 */