diff --git a/c_src/async_nif.h b/c_src/async_nif.h
index da13cd4..7601b6b 100644
--- a/c_src/async_nif.h
+++ b/c_src/async_nif.h
@@ -154,8 +154,6 @@ struct async_nif_state {
 #define ASYNC_NIF_WORK_ENV new_env
 
 #define ASYNC_NIF_REPLY(msg) enif_send(NULL, pid, env, enif_make_tuple2(env, ref, msg))
-// TODO: fix, currently NOREPLY() will block cause the recieve in async_nif.hrl wait forever
-#define ASYNC_NIF_NOREPLY() enif_free_env(env)
 
 /**
  * TODO:
@@ -246,11 +244,8 @@ async_nif_worker_fn(void *arg)
       /* and then call the post-work cleanup function. */
       req->fn_post(req->args);
 
-      /* Note: we don't call enif_free_env(req->env) because somewhere in the
-         work block there has been a call to enif_send() which invalidates the
-         environment we created which in theory will cause the next GC to free
-         it for us).  If a work block doesn't call ASYNC_NIF_REPLY() at some
-         point then it must call ASYNC_NIF_NOREPLY() to free this env. */
+      /* Free all resources allocated for this async request. */
+      enif_free_env(req->env);
       enif_free(req->args);
       enif_free(req);
       req = NULL;
@@ -301,6 +296,7 @@ async_nif_unload(ErlNifEnv *env, struct async_nif_state *async_nif)
                     enif_make_tuple2(req->env, enif_make_atom(req->env, "error"),
                                      enif_make_atom(req->env, "shutdown")));
           req->fn_post(req->args);
+          enif_free_env(req->env);
           enif_free(req->args);
           enif_free(req);
           });
diff --git a/c_src/wterl.c b/c_src/wterl.c
index 4a8992c..764db6d 100644
--- a/c_src/wterl.c
+++ b/c_src/wterl.c
@@ -299,7 +299,7 @@ ASYNC_NIF_DECL(
   { // pre
 
     if (!(argc == 3 &&
-          enif_get_string(env, argv[0], args->homedir, sizeof args->homedir, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[0], args->homedir, sizeof args->homedir, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[1]) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
@@ -448,7 +448,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -502,7 +502,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -568,8 +568,8 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 4 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->oldname, sizeof args->oldname, ERL_NIF_LATIN1) &&
-          enif_get_string(env, argv[2], args->newname, sizeof args->newname, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->oldname, sizeof args->oldname, ERL_NIF_LATIN1) > 0) &&
+          (enif_get_string(env, argv[2], args->newname, sizeof args->newname, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[3]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -635,7 +635,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -746,7 +746,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 5 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[4]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -921,7 +921,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -983,7 +983,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -1044,7 +1044,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -1099,7 +1099,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }
@@ -1170,7 +1170,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 4 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]) &&
           enif_is_binary(env, argv[3]))) {
       ASYNC_NIF_RETURN_BADARG();
@@ -1236,7 +1236,7 @@ ASYNC_NIF_DECL(
 
     if (!(argc == 3 &&
           enif_get_resource(env, argv[0], wterl_conn_RESOURCE, (void**)&args->conn_handle) &&
-          enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) &&
+          (enif_get_string(env, argv[1], args->uri, sizeof args->uri, ERL_NIF_LATIN1) > 0) &&
           enif_is_binary(env, argv[2]))) {
       ASYNC_NIF_RETURN_BADARG();
     }