diff --git a/src/libs/tools.h b/src/libs/tools.h
index ccb477b..c2b4416 100644
--- a/src/libs/tools.h
+++ b/src/libs/tools.h
@@ -39,6 +39,8 @@
 #define A_REALLOC(_dest, _nmemb)	assert((_dest = realloc(_dest, _nmemb * sizeof(*(_dest)))))
 #define MEMSET_ZERO(_obj)			memset(&(_obj), 0, sizeof(_obj))
 
+#define A_ASPRINTF(_dest, _fmt, ...) assert(asprintf(&(_dest), _fmt, ##__VA_ARGS__) >= 0)
+
 #define ARRAY_LEN(_array) (sizeof(_array) / sizeof(_array[0]))
 
 #define INLINE inline __attribute__((always_inline))
diff --git a/src/ustreamer/encoder.c b/src/ustreamer/encoder.c
index f0d94a4..db90cd6 100644
--- a/src/ustreamer/encoder.c
+++ b/src/ustreamer/encoder.c
@@ -217,9 +217,7 @@ static void *_worker_job_init(worker_s *wr, void *v_enc) {
 	A_CALLOC(job, 1);
 	job->enc = (encoder_s *)v_enc;
 
-	const size_t dest_role_len = strlen(wr->name) + 16;
-	A_CALLOC(job->dest_role, dest_role_len);
-	snprintf(job->dest_role, dest_role_len, "%s_dest", wr->name);
+	A_ASPRINTF(job->dest_role, "%s_dest", wr->name);
 	job->dest = frame_init(job->dest_role);
 
 	return (void *)job;
diff --git a/src/ustreamer/gpio/gpio.c b/src/ustreamer/gpio/gpio.c
index 41adaab..6c26106 100644
--- a/src/ustreamer/gpio/gpio.c
+++ b/src/ustreamer/gpio/gpio.c
@@ -102,8 +102,7 @@ static void _gpio_output_init(gpio_output_s *output) {
 	assert(gpio.chip);
 	assert(output->line == NULL);
 
-	A_CALLOC(output->consumer, strlen(gpio.consumer_prefix) + strlen(output->role) + 16);
-	sprintf(output->consumer, "%s::%s", gpio.consumer_prefix, output->role);
+	A_ASPRINTF(output->consumer, "%s::%s", gpio.consumer_prefix, output->role);
 
 	if (output->pin >= 0) {
 		if ((output->line = gpiod_chip_get_line(gpio.chip, output->pin)) != NULL) {
diff --git a/src/ustreamer/http/server.c b/src/ustreamer/http/server.c
index f5b3a86..163b60f 100644
--- a/src/ustreamer/http/server.c
+++ b/src/ustreamer/http/server.c
@@ -145,16 +145,14 @@ int server_listen(server_s *server) {
 	evhttp_set_timeout(RUN(http), server->timeout);
 
 	if (server->user[0] != '\0') {
-		char *raw_token;
 		char *encoded_token = NULL;
 
-		A_CALLOC(raw_token, strlen(server->user) + strlen(server->passwd) + 16);
-		sprintf(raw_token, "%s:%s", server->user, server->passwd);
+		char *raw_token;
+		A_ASPRINTF(raw_token, "%s:%s", server->user, server->passwd);
 		base64_encode((uint8_t *)raw_token, strlen(raw_token), &encoded_token, NULL);
 		free(raw_token);
 
-		A_CALLOC(RUN(auth_token), strlen(encoded_token) + 16);
-		sprintf(RUN(auth_token), "Basic %s", encoded_token);
+		A_ASPRINTF(RUN(auth_token), "Basic %s", encoded_token);
 		free(encoded_token);
 
 		LOG_INFO("Using HTTP basic auth");
@@ -857,10 +855,7 @@ static char *_http_get_client_hostport(struct evhttp_request *request) {
 	}
 
 	char *hostport;
-	size_t hostport_len = strlen(addr) + 64;
-	A_CALLOC(hostport, hostport_len);
-
-	snprintf(hostport, hostport_len, "[%s]:%u", addr, port);
+	A_ASPRINTF(hostport, "[%s]:%u", addr, port);
 	free(addr);
 	return hostport;
 }
diff --git a/src/ustreamer/http/static.c b/src/ustreamer/http/static.c
index 9a83785..02ab601 100644
--- a/src/ustreamer/http/static.c
+++ b/src/ustreamer/http/static.c
@@ -32,7 +32,7 @@ char *find_static_file_path(const char *root_path, const char *request_path) {
 		goto error;
 	}
 
-	A_CALLOC(path, strlen(root_path) + strlen(simplified_path) + 16);
+	A_CALLOC(path, strlen(root_path) + strlen(simplified_path) + 16); // + reserved for /index.html
 	sprintf(path, "%s/%s", root_path, simplified_path);
 
 	struct stat st;
diff --git a/src/ustreamer/workers.c b/src/ustreamer/workers.c
index b618d49..dab87d0 100644
--- a/src/ustreamer/workers.c
+++ b/src/ustreamer/workers.c
@@ -49,14 +49,11 @@ workers_pool_s *workers_pool_init(
 	A_MUTEX_INIT(&pool->free_workers_mutex);
 	A_COND_INIT(&pool->free_workers_cond);
 
-	const size_t wr_name_len = strlen(wr_prefix) + 64;
-
 	for (unsigned number = 0; number < pool->n_workers; ++number) {
 #		define WR(_next) pool->workers[number]._next
 
 		WR(number) = number;
-		A_CALLOC(WR(name), wr_name_len);
-		snprintf(WR(name), wr_name_len, "%s-%u", wr_prefix, number);
+		A_ASPRINTF(WR(name), "%s-%u", wr_prefix, number);
 
 		A_MUTEX_INIT(&WR(has_job_mutex));
 		atomic_init(&WR(has_job), false);