diff --git a/DESCRIPTION b/DESCRIPTION
index 5f7adc6a1..d533efdbd 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: nanonext
 Type: Package
 Title: NNG (Nanomsg Next Gen) Lightweight Messaging Library
-Version: 1.2.1.9024
+Version: 1.2.1.9025
 Description: R binding for NNG (Nanomsg Next Gen), a successor to ZeroMQ. NNG is
     a socket library implementing 'Scalability Protocols', a reliable,
     high-performance standard for common communications patterns including
diff --git a/NEWS.md b/NEWS.md
index c638e6a07..22ef8475b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,4 +1,4 @@
-# nanonext 1.2.1.9024 (development)
+# nanonext 1.2.1.9025 (development)
 
 #### New Features
 
@@ -10,7 +10,7 @@
 * Warning messages for unserialization or conversion failures of received data are now suppressable.
 * Upgrades `reply()` to always return even when there is an evaluation error. This allows it to be used safely in a loop without exiting early, for example.
 * Removes deprecated and defunct `next_config()`.
-* Performance enhancements for `promises::as.promise()` methods.
+* Internal performance enhancements.
 * Updates bundled 'libnng' v1.8.0 with latest patches.
 
 # nanonext 1.2.1
diff --git a/src/comms.c b/src/comms.c
index cf8c95b68..e0ecbc830 100644
--- a/src/comms.c
+++ b/src/comms.c
@@ -112,42 +112,42 @@ SEXP rnng_dial(SEXP socket, SEXP url, SEXP tls, SEXP autostart, SEXP error) {
   nng_socket *sock = (nng_socket *) NANO_PTR(socket);
   const int start = NANO_INTEGER(autostart);
   const char *ur = CHAR(STRING_ELT(url, 0));
-  nano_dialer *dp = R_Calloc(1, nano_dialer);
-  SEXP dialer, attr, newattr;
+  nng_dialer *dp = R_Calloc(1, nng_dialer);
+  SEXP dialer, attr, newattr, xp;
+  nng_tls_config *cfg;
   nng_url *up;
   int xc;
 
   if (sec) {
-    if ((xc = nng_dialer_create(&dp->dial, *sock, ur)))
+    if ((xc = nng_dialer_create(dp, *sock, ur)) ||
+        (xc = nng_url_parse(&up, ur)))
       goto exitlevel1;
-    dp->tls = (nng_tls_config *) NANO_PTR(tls);
-    nng_tls_config_hold(dp->tls);
-    if ((xc = nng_url_parse(&up, ur)))
+    cfg = (nng_tls_config *) NANO_PTR(tls);
+    if ((xc = nng_tls_config_server_name(cfg, up->u_hostname)) ||
+        (xc = nng_dialer_set_ptr(*dp, NNG_OPT_TLS_CONFIG, cfg)))
       goto exitlevel2;
-    if ((xc = nng_tls_config_server_name(dp->tls, up->u_hostname)) ||
-        (xc = nng_dialer_set_ptr(dp->dial, NNG_OPT_TLS_CONFIG, dp->tls)))
-      goto exitlevel3;
     nng_url_free(up);
-  }
+    if (start && (xc = nng_dialer_start(*dp, start == 1 ? NNG_FLAG_NONBLOCK : 0)))
+        goto exitlevel1;
+    nng_tls_config_hold(cfg);
 
-  switch (start) {
-  case 0:
-    xc = sec ? 0 : nng_dialer_create(&dp->dial, *sock, ur);
-    break;
-  case 1:
-    xc = sec ? nng_dialer_start(dp->dial, NNG_FLAG_NONBLOCK) : nng_dial(*sock, ur, &dp->dial, NNG_FLAG_NONBLOCK);
-    break;
-  default:
-    xc = sec ? nng_dialer_start(dp->dial, 0) : nng_dial(*sock, ur, &dp->dial, 0);
-  }
-  if (xc)
-    goto exitlevel1;
+    PROTECT_INDEX pxi;
+    PROTECT_WITH_INDEX(xp = R_MakeExternalPtr(cfg, nano_TlsSymbol, R_NilValue), &pxi);
+    R_RegisterCFinalizerEx(xp, tls_finalizer, TRUE);
+    REPROTECT(dialer = R_MakeExternalPtr(dp, nano_DialerSymbol, xp), pxi);
+
+  } else {
 
-  PROTECT(dialer = R_MakeExternalPtr(dp, nano_DialerSymbol, R_NilValue));
+    if ((xc = start ? nng_dial(*sock, ur, dp, start == 1 ? NNG_FLAG_NONBLOCK : 0) : nng_dialer_create(dp, *sock, ur)))
+      goto exitlevel1;
+
+    PROTECT(dialer = R_MakeExternalPtr(dp, nano_DialerSymbol, R_NilValue));
+
+  }
   R_RegisterCFinalizerEx(dialer, dialer_finalizer, TRUE);
 
   NANO_CLASS2(dialer, "nanoDialer", "nano");
-  Rf_setAttrib(dialer, nano_IdSymbol, Rf_ScalarInteger(nng_dialer_id(dp->dial)));
+  Rf_setAttrib(dialer, nano_IdSymbol, Rf_ScalarInteger(nng_dialer_id(*dp)));
   Rf_setAttrib(dialer, nano_UrlSymbol, url);
   Rf_setAttrib(dialer, nano_StateSymbol, Rf_mkString(start ? "started" : "not started"));
   Rf_setAttrib(dialer, nano_SocketSymbol, Rf_ScalarInteger(nng_socket_id(*sock)));
@@ -164,10 +164,8 @@ SEXP rnng_dial(SEXP socket, SEXP url, SEXP tls, SEXP autostart, SEXP error) {
   UNPROTECT(2);
   return nano_success;
 
-  exitlevel3:
-  nng_url_free(up);
   exitlevel2:
-  nng_tls_config_free(dp->tls);
+  nng_url_free(up);
   exitlevel1:
   R_Free(dp);
   if (NANO_INTEGER(error)) ERROR_OUT(xc);
@@ -188,37 +186,43 @@ SEXP rnng_listen(SEXP socket, SEXP url, SEXP tls, SEXP autostart, SEXP error) {
   nng_socket *sock = (nng_socket *) NANO_PTR(socket);
   const int start = NANO_INTEGER(autostart);
   const char *ur = CHAR(STRING_ELT(url, 0));
-  nano_listener *lp = R_Calloc(1, nano_listener);
-  SEXP listener, attr, newattr;
+  nng_listener *lp = R_Calloc(1, nng_listener);
+  SEXP listener, attr, newattr, xp;
+  nng_tls_config *cfg;
   nng_url *up;
   int xc;
 
   if (sec) {
-    if ((xc = nng_listener_create(&lp->list, *sock, ur)))
+    if ((xc = nng_listener_create(lp, *sock, ur)) ||
+        (xc = nng_url_parse(&up, ur)))
       goto exitlevel1;
-    lp->tls = (nng_tls_config *) NANO_PTR(tls);
-    nng_tls_config_hold(lp->tls);
-    if ((xc = nng_url_parse(&up, ur)))
+    cfg = (nng_tls_config *) NANO_PTR(tls);
+    if ((xc = nng_tls_config_server_name(cfg, up->u_hostname)) ||
+        (xc = nng_listener_set_ptr(*lp, NNG_OPT_TLS_CONFIG, cfg)))
       goto exitlevel2;
-    if ((xc = nng_tls_config_server_name(lp->tls, up->u_hostname)) ||
-        (xc = nng_listener_set_ptr(lp->list, NNG_OPT_TLS_CONFIG, lp->tls)))
-      goto exitlevel3;
     nng_url_free(up);
-  }
+    if (start && (xc = nng_listener_start(*lp, 0)))
+      goto exitlevel1;
+    nng_tls_config_hold(cfg);
+
+    PROTECT_INDEX pxi;
+    PROTECT_WITH_INDEX(xp = R_MakeExternalPtr(cfg, nano_TlsSymbol, R_NilValue), &pxi);
+    R_RegisterCFinalizerEx(xp, tls_finalizer, TRUE);
+    REPROTECT(listener = R_MakeExternalPtr(lp, nano_ListenerSymbol, xp), pxi);
 
-  if (start) {
-    xc = sec ? nng_listener_start(lp->list, 0) : nng_listen(*sock, ur, &lp->list, 0);
   } else {
-    xc = sec ? 0 : nng_listener_create(&lp->list, *sock, ur);
+
+    if ((xc = start ? nng_listen(*sock, ur, lp, 0) : nng_listener_create(lp, *sock, ur)))
+      goto exitlevel1;
+
+    PROTECT(listener = R_MakeExternalPtr(lp, nano_ListenerSymbol, R_NilValue));
+
   }
-  if (xc)
-    goto exitlevel1;
 
-  PROTECT(listener = R_MakeExternalPtr(lp, nano_ListenerSymbol, R_NilValue));
   R_RegisterCFinalizerEx(listener, listener_finalizer, TRUE);
 
   NANO_CLASS2(listener, "nanoListener", "nano");
-  Rf_setAttrib(listener, nano_IdSymbol, Rf_ScalarInteger(nng_listener_id(lp->list)));
+  Rf_setAttrib(listener, nano_IdSymbol, Rf_ScalarInteger(nng_listener_id(*lp)));
   Rf_setAttrib(listener, nano_UrlSymbol, url);
   Rf_setAttrib(listener, nano_StateSymbol, Rf_mkString(start ? "started" : "not started"));
   Rf_setAttrib(listener, nano_SocketSymbol, Rf_ScalarInteger(nng_socket_id(*sock)));
@@ -235,10 +239,8 @@ SEXP rnng_listen(SEXP socket, SEXP url, SEXP tls, SEXP autostart, SEXP error) {
   UNPROTECT(2);
   return nano_success;
 
-  exitlevel3:
-  nng_url_free(up);
   exitlevel2:
-  nng_tls_config_free(lp->tls);
+  nng_url_free(up);
   exitlevel1:
   R_Free(lp);
   if (NANO_INTEGER(error)) ERROR_OUT(xc);
diff --git a/src/core.c b/src/core.c
index 972cff115..3e08d839b 100644
--- a/src/core.c
+++ b/src/core.c
@@ -149,13 +149,21 @@ void sendaio_complete(void *arg) {
 
 }
 
+void cv_finalizer(SEXP xptr) {
+
+  if (NANO_PTR(xptr) == NULL) return;
+  nano_cv *xp = (nano_cv *) NANO_PTR(xptr);
+  nng_cv_free(xp->cv);
+  nng_mtx_free(xp->mtx);
+  R_Free(xp);
+
+}
+
 void dialer_finalizer(SEXP xptr) {
 
   if (NANO_PTR(xptr) == NULL) return;
-  nano_dialer *xp = (nano_dialer *) NANO_PTR(xptr);
-  nng_dialer_close(xp->dial);
-  if (xp->tls != NULL)
-    nng_tls_config_free(xp->tls);
+  nng_dialer *xp = (nng_dialer *) NANO_PTR(xptr);
+  nng_dialer_close(*xp);
   R_Free(xp);
 
 }
@@ -163,10 +171,8 @@ void dialer_finalizer(SEXP xptr) {
 void listener_finalizer(SEXP xptr) {
 
   if (NANO_PTR(xptr) == NULL) return;
-  nano_listener *xp = (nano_listener *) NANO_PTR(xptr);
-  nng_listener_close(xp->list);
-  if (xp->tls != NULL)
-    nng_tls_config_free(xp->tls);
+  nng_listener *xp = (nng_listener *) NANO_PTR(xptr);
+  nng_listener_close(*xp);
   R_Free(xp);
 
 }
@@ -180,13 +186,11 @@ void socket_finalizer(SEXP xptr) {
 
 }
 
-void cv_finalizer(SEXP xptr) {
+void tls_finalizer(SEXP xptr) {
 
   if (NANO_PTR(xptr) == NULL) return;
-  nano_cv *xp = (nano_cv *) NANO_PTR(xptr);
-  nng_cv_free(xp->cv);
-  nng_mtx_free(xp->mtx);
-  R_Free(xp);
+  nng_tls_config *xp = (nng_tls_config *) NANO_PTR(xptr);
+  nng_tls_config_free(xp);
 
 }
 
diff --git a/src/nanonext.h b/src/nanonext.h
index 1045169b2..8acf5791e 100644
--- a/src/nanonext.h
+++ b/src/nanonext.h
@@ -137,16 +137,6 @@ typedef union nano_opt_u {
   uint64_t u;
 } nano_opt;
 
-typedef struct nano_listener_s {
-  nng_listener list;
-  nng_tls_config *tls;
-} nano_listener;
-
-typedef struct nano_dialer_s {
-  nng_dialer dial;
-  nng_tls_config *tls;
-} nano_dialer;
-
 typedef struct nano_stream_s {
   nng_stream *stream;
   union {
@@ -303,6 +293,7 @@ int nano_matcharg(const SEXP);
 int nano_matchargs(const SEXP);
 
 void pipe_cb_signal(nng_pipe, nng_pipe_ev, void *);
+void tls_finalizer(SEXP);
 
 SEXP rnng_advance_rng_state(void);
 SEXP rnng_aio_call(SEXP);
diff --git a/src/thread.c b/src/thread.c
index 8cd31ca4c..fbde57ba3 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -115,22 +115,22 @@ SEXP rnng_messenger(SEXP url) {
 
   const char *up = CHAR(STRING_ELT(url, 0));
   nng_socket *sock = R_Calloc(1, nng_socket);
-  nano_listener *lp;
-  nano_dialer *dp;
+  nng_listener *lp;
+  nng_dialer *dp;
   int xc, dialer = 0;
   SEXP socket, con;
 
   if ((xc = nng_pair0_open(sock)))
     goto exitlevel1;
-  lp = R_Calloc(1, nano_listener);
-  if ((xc = nng_listen(*sock, up, &lp->list, 0))) {
+  lp = R_Calloc(1, nng_listener);
+  if ((xc = nng_listen(*sock, up, lp, 0))) {
     if (xc != 10 && xc != 15) {
       R_Free(lp);
       goto exitlevel1;
     }
     R_Free(lp);
-    dp = R_Calloc(1, nano_dialer);
-    if ((xc = nng_dial(*sock, up, &dp->dial, 0))) {
+    dp = R_Calloc(1, nng_dialer);
+    if ((xc = nng_dial(*sock, up, dp, 0))) {
       R_Free(dp);
       goto exitlevel1;
     }
@@ -699,7 +699,7 @@ SEXP rnng_dispatcher_socket(SEXP host, SEXP url, SEXP tls) {
     memcpy(disp->url[i], up, slen);
   }
   nng_socket *hsock = R_Calloc(1, nng_socket);
-  nano_listener *hl = R_Calloc(1, nano_listener);
+  nng_listener *hl = R_Calloc(1, nng_listener);
 
   if (nng_url_parse(&disp->up, disp->url[0]))
     goto exitlevel3;
@@ -708,7 +708,7 @@ SEXP rnng_dispatcher_socket(SEXP host, SEXP url, SEXP tls) {
     goto exitlevel4;
 
   if ((xc = nng_socket_set_ms(*hsock, "req:resend-time", 0)) ||
-      (xc = nng_listen(*hsock, disp->host, &hl->list, 0)) ||
+      (xc = nng_listen(*hsock, disp->host, hl, 0)) ||
       (xc = nng_thread_create(&disp->thr, rnng_dispatch_thread, disp)))
     goto exitlevel5;
 
diff --git a/src/tls.c b/src/tls.c
index 7c307d7d0..f97b78fb7 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -76,16 +76,6 @@ static int parse_serial_decimal_format(unsigned char *obuf, size_t obufmax,
 }
 #endif
 
-// finalizers ------------------------------------------------------------------
-
-static void tls_finalizer(SEXP xptr) {
-
-  if (NANO_PTR(xptr) == NULL) return;
-  nng_tls_config *xp = (nng_tls_config *) NANO_PTR(xptr);
-  nng_tls_config_free(xp);
-
-}
-
 // Mbed TLS Random Data Generator ----------------------------------------------
 
 SEXP rnng_random(SEXP n, SEXP convert) {