diff --git a/cgminer.c b/cgminer.c
index ef7bf3b6..ae976b1b 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -5086,30 +5086,26 @@ static void set_work_target(struct work *work, double diff)
 static void gen_stratum_work(struct pool *pool, struct work *work)
 {
 	unsigned char *coinbase, merkle_root[32], merkle_sha[64];
-	int len, cb1_len, n1_len, cb2_len, i;
 	char *header, *merkle_hash;
 	uint32_t *data32, *swap32;
 	size_t alloc_len;
+	int i;
 
 	mutex_lock(&pool->pool_lock);
 
 	/* Generate coinbase */
 	work->nonce2 = bin2hex((const unsigned char *)&pool->nonce2, pool->n2size);
 	pool->nonce2++;
-	cb1_len = strlen(pool->swork.coinbase1) / 2;
-	n1_len = strlen(pool->nonce1) / 2;
-	cb2_len = strlen(pool->swork.coinbase2) / 2;
-	len = cb1_len + n1_len + pool->n2size + cb2_len;
-	alloc_len = len;
+	alloc_len = pool->swork.cb_len;
 	align_len(&alloc_len);
 	coinbase = calloc(alloc_len, 1);
-	hex2bin(coinbase, pool->swork.coinbase1, cb1_len);
-	hex2bin(coinbase + cb1_len, pool->nonce1, n1_len);
-	hex2bin(coinbase + cb1_len + n1_len, work->nonce2, pool->n2size);
-	hex2bin(coinbase + cb1_len + n1_len + pool->n2size, pool->swork.coinbase2, cb2_len);
+	hex2bin(coinbase, pool->swork.coinbase1, pool->swork.cb1_len);
+	hex2bin(coinbase + pool->swork.cb1_len, pool->nonce1, pool->n1_len);
+	hex2bin(coinbase + pool->swork.cb1_len + pool->n1_len, work->nonce2, pool->n2size);
+	hex2bin(coinbase + pool->swork.cb1_len + pool->n1_len + pool->n2size, pool->swork.coinbase2, pool->swork.cb2_len);
 
 	/* Generate merkle root */
-	gen_hash(coinbase, merkle_root, len);
+	gen_hash(coinbase, merkle_root, pool->swork.cb_len);
 	free(coinbase);
 	memcpy(merkle_sha, merkle_root, 32);
 	for (i = 0; i < pool->swork.merkles; i++) {
diff --git a/miner.h b/miner.h
index 8dbffa5e..e9982b7a 100644
--- a/miner.h
+++ b/miner.h
@@ -855,6 +855,10 @@ struct stratum_work {
 	char *ntime;
 	bool clean;
 
+	size_t cb1_len;
+	size_t cb2_len;
+	size_t cb_len;
+
 	size_t header_len;
 	int merkles;
 	double diff;
@@ -934,6 +938,7 @@ struct pool {
 	size_t sockbuf_size;
 	char *sockaddr_url; /* stripped url used for sockaddr */
 	char *nonce1;
+	size_t n1_len;
 	uint32_t nonce2;
 	int n2size;
 	bool has_stratum;
diff --git a/util.c b/util.c
index dd99e1b1..7e84c537 100644
--- a/util.c
+++ b/util.c
@@ -1131,11 +1131,15 @@ static bool parse_notify(struct pool *pool, json_t *val)
 	pool->swork.job_id = job_id;
 	pool->swork.prev_hash = prev_hash;
 	pool->swork.coinbase1 = coinbase1;
+	pool->swork.cb1_len = strlen(coinbase1) / 2;
 	pool->swork.coinbase2 = coinbase2;
+	pool->swork.cb2_len = strlen(coinbase2) / 2;
 	pool->swork.bbversion = bbversion;
 	pool->swork.nbit = nbit;
 	pool->swork.ntime = ntime;
 	pool->swork.clean = clean;
+	pool->swork.cb_len = pool->swork.cb1_len + pool->n1_len + pool->n2size + pool->swork.cb2_len;
+
 	for (i = 0; i < pool->swork.merkles; i++)
 		free(pool->swork.merkle[i]);
 	if (merkles) {
@@ -1468,6 +1472,7 @@ bool initiate_stratum(struct pool *pool)
 		applog(LOG_INFO, "Failed to get nonce1 in initiate_stratum");
 		goto out;
 	}
+	pool->n1_len = strlen(pool->nonce1) / 2;
 	pool->n2size = json_integer_value(json_array_get(res_val, 2));
 	if (!pool->n2size) {
 		applog(LOG_INFO, "Failed to get n2size in initiate_stratum");