diff --git a/src/core.c b/src/core.c
index a59214d7c..8a09a26a2 100644
--- a/src/core.c
+++ b/src/core.c
@@ -503,10 +503,10 @@ void nano_encode(nano_buf *enc, const SEXP object) {
     R_xlen_t i;
     size_t slen, outlen = 0;
     for (i = 0; i < xlen; i++)
-      outlen += strlen(CHAR(STRING_ELT(object, i))) + 1;
+      outlen += strlen(NANO_STR_N(object, i)) + 1;
     NANO_ALLOC(enc, outlen);
     for (i = 0; i < xlen; i++) {
-      s = CHAR(STRING_ELT(object, i));
+      s = NANO_STR_N(object, i);
       slen = strlen(s) + 1;
       memcpy(enc->buf + enc->cur, s, slen);
       enc->cur += slen;
@@ -595,7 +595,7 @@ int nano_matcharg(const SEXP mode) {
 int nano_matchargs(const SEXP mode) {
 
   if (TYPEOF(mode) != INTSXP) {
-    const char *mod = CHAR(STRING_ELT(mode, XLENGTH(mode) == 9));
+    const char *mod = NANO_STR_N(mode, XLENGTH(mode) == 9);
     size_t slen = strlen(mod);
     switch (slen) {
     case 1:
diff --git a/src/nanonext.h b/src/nanonext.h
index d147f6fce..4f1bd1e08 100644
--- a/src/nanonext.h
+++ b/src/nanonext.h
@@ -96,6 +96,7 @@ typedef struct nano_handle_s {
 #define NANO_DATAPTR(x) (void *) DATAPTR_RO(x)
 #define NANO_VECTOR(x) ((const SEXP *) DATAPTR_RO(x))
 #define NANO_STRING(x) CHAR(*((const SEXP *) DATAPTR_RO(x)))
+#define NANO_STR_N(x, n) CHAR(((const SEXP *) DATAPTR_RO(x))[n])
 #define NANO_INTEGER(x) *(int *) DATAPTR_RO(x)
 #define NANO_ERROR(x) { Rf_error(x); return R_NilValue; }
 
diff --git a/src/ncurl.c b/src/ncurl.c
index 1e68d5172..6d978fa20 100644
--- a/src/ncurl.c
+++ b/src/ncurl.c
@@ -168,8 +168,8 @@ SEXP rnng_ncurl(SEXP http, SEXP convert, SEXP follow, SEXP method, SEXP headers,
     if (TYPEOF(hnames) == STRSXP && XLENGTH(hnames) == hlen) {
       for (R_xlen_t i = 0; i < hlen; i++) {
         if ((xc = nng_http_req_set_header(req,
-                                          CHAR(STRING_ELT(hnames, i)),
-                                          CHAR(STRING_ELT(headers, i)))))
+                                          NANO_STR_N(hnames, i),
+                                          NANO_STR_N(headers, i))))
           goto exitlevel4;
       }
     }
@@ -262,7 +262,7 @@ SEXP rnng_ncurl(SEXP http, SEXP convert, SEXP follow, SEXP method, SEXP headers,
     SET_VECTOR_ELT(out, 1, rvec);
     Rf_namesgets(rvec, response);
     for (R_xlen_t i = 0; i < rlen; i++) {
-      const char *r = nng_http_res_get_header(res, CHAR(STRING_ELT(response, i)));
+      const char *r = nng_http_res_get_header(res, NANO_STR_N(response, i));
       SET_VECTOR_ELT(rvec, i, r == NULL ? R_NilValue : Rf_mkString(r));
     }
   } else {
@@ -343,8 +343,8 @@ SEXP rnng_ncurl_aio(SEXP http, SEXP convert, SEXP method, SEXP headers, SEXP dat
     if (TYPEOF(hnames) == STRSXP && XLENGTH(hnames) == hlen) {
       for (R_xlen_t i = 0; i < hlen; i++) {
         if ((xc = nng_http_req_set_header(handle->req,
-                                          CHAR(STRING_ELT(hnames, i)),
-                                          CHAR(STRING_ELT(headers, i)))))
+                                          NANO_STR_N(hnames, i),
+                                          NANO_STR_N(headers, i))))
           goto exitlevel4;
       }
     }
@@ -476,7 +476,7 @@ static SEXP rnng_aio_http_impl(SEXP env, const int typ) {
     PROTECT(rvec = Rf_allocVector(VECSXP, rlen));
     Rf_namesgets(rvec, response);
     for (R_xlen_t i = 0; i < rlen; i++) {
-      const char *r = nng_http_res_get_header(handle->res, CHAR(STRING_ELT(response, i)));
+      const char *r = nng_http_res_get_header(handle->res, NANO_STR_N(response, i));
       SET_VECTOR_ELT(rvec, i, r == NULL ? R_NilValue : Rf_mkString(r));
     }
     UNPROTECT(1);
@@ -557,8 +557,8 @@ SEXP rnng_ncurl_session(SEXP http, SEXP convert, SEXP method, SEXP headers, SEXP
     if (TYPEOF(hnames) == STRSXP && XLENGTH(hnames) == hlen) {
       for (R_xlen_t i = 0; i < hlen; i++) {
         if ((xc = nng_http_req_set_header(handle->req,
-                                          CHAR(STRING_ELT(hnames, i)),
-                                          CHAR(STRING_ELT(headers, i)))))
+                                          NANO_STR_N(hnames, i),
+                                          NANO_STR_N(headers, i))))
           goto exitlevel4;
       }
     }
@@ -670,7 +670,7 @@ SEXP rnng_ncurl_transact(SEXP session) {
     SET_VECTOR_ELT(out, 1, rvec);
     Rf_namesgets(rvec, response);
     for (R_xlen_t i = 0; i < rlen; i++) {
-      const char *r = nng_http_res_get_header(handle->res, CHAR(STRING_ELT(response, i)));
+      const char *r = nng_http_res_get_header(handle->res, NANO_STR_N(response, i));
       SET_VECTOR_ELT(rvec, i, r == NULL ? R_NilValue : Rf_mkString(r));
     }
   } else {
diff --git a/src/tls.c b/src/tls.c
index 3daf68831..0b2850ef8 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -296,7 +296,7 @@ SEXP rnng_tls_config(SEXP client, SEXP server, SEXP pass, SEXP auth) {
   if ((usefile = Rf_xlength(client)) > 0) {
     file = NANO_STRING(client);
     if (usefile > 1)
-      crl = CHAR(STRING_ELT(client, 1));
+      crl = NANO_STR_N(client, 1);
     if ((xc = nng_tls_config_alloc(&cfg, NNG_TLS_MODE_CLIENT)))
       goto exitlevel1;
     if ((xc = nng_tls_config_auth_mode(cfg, mod)))
@@ -315,7 +315,7 @@ SEXP rnng_tls_config(SEXP client, SEXP server, SEXP pass, SEXP auth) {
     file = NANO_STRING(server);
     pss = pass != R_NilValue ? NANO_STRING(pass) : NULL;
     if (usefile > 1)
-      key = CHAR(STRING_ELT(server, 1));
+      key = NANO_STR_N(server, 1);
     if ((xc = nng_tls_config_alloc(&cfg, NNG_TLS_MODE_SERVER)))
       goto exitlevel1;
     if ((xc = nng_tls_config_auth_mode(cfg, mod)))
diff --git a/src/utils.c b/src/utils.c
index 3c601c5bd..06ce11cff 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -501,7 +501,7 @@ SEXP rnng_next_config(SEXP refhook, SEXP klass, SEXP list, SEXP mark) {
 
     SETCAR(nano_refHook, plist ? CAR(refhook) : NANO_VECTOR(refhook)[0]);
     SETCADR(nano_refHook, plist ? CADR(refhook) : NANO_VECTOR(refhook)[1]);
-    SETCAR(nano_klassString, STRING_ELT(klass, 0));
+    SETCAR(nano_klassString, *NANO_VECTOR(klass));
 
     registered = NANO_INTEGER(list) ? 1 : 2;