diff --git a/src/datum_coinbaser.c b/src/datum_coinbaser.c
index a8c8f1d..09cff6b 100644
--- a/src/datum_coinbaser.c
+++ b/src/datum_coinbaser.c
@@ -305,7 +305,7 @@ void generate_coinbase_txns_for_stratum_job_subtypebysize(T_DATUM_STRATUM_JOB *s
 	
 	// witness commit output costs 46 bytes
 	// append the default_witness_commitment
-	cb2idx[coinbase_index] += sprintf(&s->coinbase[coinbase_index].coinb2[cb2idx[coinbase_index]], "0000000000000000%2.2x%s", (unsigned char)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
+	cb2idx[coinbase_index] += sprintf(&s->coinbase[coinbase_index].coinb2[cb2idx[coinbase_index]], "0000000000000000%2.2x%s", (unsigned int)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
 	// lock time
 	cb2idx[coinbase_index] += sprintf(&s->coinbase[coinbase_index].coinb2[cb2idx[coinbase_index]], "00000000");
 }
@@ -453,7 +453,7 @@ void generate_base_coinbase_txns_for_stratum_job(T_DATUM_STRATUM_JOB *s, bool ne
 	
 	// witness commit output costs 46 bytes
 	// append the default_witness_commitment
-	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "0000000000000000%2.2x%s", (unsigned char)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
+	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "0000000000000000%2.2x%s", (unsigned int)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
 	// lock time
 	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "00000000");
 	
@@ -659,7 +659,7 @@ void generate_coinbase_txns_for_stratum_job(T_DATUM_STRATUM_JOB *s, bool empty_o
 	
 	// witness commit output costs 46 bytes
 	// append the default_witness_commitment
-	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "0000000000000000%2.2x%s", (unsigned char)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
+	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "0000000000000000%2.2x%s", (unsigned int)strlen(s->block_template->default_witness_commitment)>>1, s->block_template->default_witness_commitment);
 	// lock time
 	cb2idx[0] += sprintf(&s->coinbase[0].coinb2[cb2idx[0]], "00000000");
 	
diff --git a/src/datum_stratum.c b/src/datum_stratum.c
index d6ed789..0b12629 100644
--- a/src/datum_stratum.c
+++ b/src/datum_stratum.c
@@ -1534,7 +1534,7 @@ int send_mining_notify(T_DATUM_CLIENT_DATA *c, bool clean, bool quickdiff, bool
 		if (!new_block) {
 			snprintf(s, sizeof(s), "\"%s%2.2x\",\"%s\",\"", j->job_id, cbselect, j->prevhash);
 		} else {
-			snprintf(s, sizeof(s), "\"N%s%2.2x\",\"%s\",\"", j->job_id, 255, j->prevhash); // empty coinbase for new block
+			snprintf(s, sizeof(s), "\"N%s%2.2x\",\"%s\",\"", j->job_id, (unsigned int)255, j->prevhash); // empty coinbase for new block
 			cb = &j->subsidy_only_coinbase;
 		}
 	}
@@ -2076,7 +2076,7 @@ void update_stratum_job(T_DATUM_TEMPLATE_DATA *block_template, bool new_block, i
 	}
 	
 	s->global_index = global_latest_stratum_job_index;
-	snprintf(s->job_id, sizeof(s->job_id), "%8.8x%2.2x%4.4x", (uint32_t)time(NULL), (uint8_t)stratum_job_next, (uint16_t)s->global_index ^ STRATUM_JOB_INDEX_XOR);
+	snprintf(s->job_id, sizeof(s->job_id), "%8.8x%2.2x%4.4x", (uint32_t)time(NULL), (uint8_t)stratum_job_next, (unsigned int)((uint16_t)s->global_index ^ STRATUM_JOB_INDEX_XOR));
 	
 	global_cur_stratum_jobs[global_latest_stratum_job_index] = s;
 	pthread_rwlock_unlock(&stratum_global_job_ptr_lock);