diff --git a/lib/nodes/kafka.cpp b/lib/nodes/kafka.cpp
index 7734e8d23..ec4ce77a3 100644
--- a/lib/nodes/kafka.cpp
+++ b/lib/nodes/kafka.cpp
@@ -67,20 +67,20 @@ static void kafka_logger_cb(const rd_kafka_t *rk, int level, const char *fac, co
 
 static void kafka_message_cb(void *ctx, const rd_kafka_message_t *msg)
 {
-	int ret;
+	int ret, cnt = n->in.vectorize;
 	struct vnode *n = (struct vnode *) ctx;
 	struct kafka *k = (struct kafka *) n->_vd;
-	struct sample *smps[n->in.vectorize];
+	struct sample *smps[cnt];
 
 	n->logger->debug("Received a message of {} bytes from broker {}", msg->len, k->server);
 
-	ret = sample_alloc_many(&k->pool, smps, n->in.vectorize);
+	ret = sample_alloc_many(&k->pool, smps, cnt);
 	if (ret <= 0) {
 		n->logger->warn("Pool underrun in consumer");
 		return;
 	}
 
-	ret = k->formatter->sscan((char *) msg->payload, msg->len, nullptr, smps, n->in.vectorize);
+	ret = k->formatter->sscan((char *) msg->payload, msg->len, nullptr, smps, cnt);
 	if (ret < 0) {
 		n->logger->warn("Received an invalid message");
 		n->logger->warn("  Payload: {}", (char *) msg->payload);
@@ -89,11 +89,11 @@ static void kafka_message_cb(void *ctx, const rd_kafka_message_t *msg)
 
 	if (ret == 0) {
 		n->logger->debug("Skip empty message");
-		sample_decref_many(smps, n->in.vectorize);
+		sample_decref_many(smps, cnt);
 		return;
 	}
 
-	ret = queue_signalled_push_many(&k->queue, (void **) smps, n->in.vectorize);
+	ret = queue_signalled_push_many(&k->queue, (void **) smps, cnt);
 	if (ret < (int) n->in.vectorize)
 		n->logger->warn("Failed to enqueue samples");
 }