diff --git a/ckpool.conf b/ckpool.conf
index ed823703..fffa2571 100644
--- a/ckpool.conf
+++ b/ckpool.conf
@@ -11,7 +11,7 @@
 		"pass" : "pass"
 	}
 ],
-"btcaddress" : "15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ",
+"btcaddress" : "14BMjogz69qe8hk9thyzbmR5pg34mVKB1e",
 "btcsig" : "/mined by ck/",
 "blockpoll" : 500,
 "update_interval" : 30,
diff --git a/src/bitcoin.c b/src/bitcoin.c
index 8a7e2f23..3f22e2ac 100644
--- a/src/bitcoin.c
+++ b/src/bitcoin.c
@@ -68,7 +68,7 @@ bool validate_address(connsock_t *cs, const char *address)
 		goto out;
 	}
 	if (!json_is_true(valid_val))
-		LOGWARNING("Bitcoin address %s is NOT valid", address);
+		LOGDEBUG("Bitcoin address %s is NOT valid", address);
 	else {
 		LOGDEBUG("Bitcoin address %s IS valid", address);
 		ret = true;
diff --git a/src/ckpool.c b/src/ckpool.c
index c4dc5c04..090c5b56 100644
--- a/src/ckpool.c
+++ b/src/ckpool.c
@@ -1200,8 +1200,9 @@ int main(int argc, char **argv)
 		}
 	}
 
+	ckp.donaddress = "14BMjogz69qe8hk9thyzbmR5pg34mVKB1e";
 	if (!ckp.btcaddress)
-		ckp.btcaddress = strdup("15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ");
+		ckp.btcaddress = ckp.donaddress;
 	if (!ckp.blockpoll)
 		ckp.blockpoll = 500;
 	if (!ckp.update_interval)
diff --git a/src/ckpool.h b/src/ckpool.h
index 8c708cb8..b1cd43fa 100644
--- a/src/ckpool.h
+++ b/src/ckpool.h
@@ -152,6 +152,8 @@ struct ckpool_instance {
 	/* Coinbase data */
 	char *btcaddress; // Address to mine to
 	char *btcsig; // Optional signature to add to coinbase
+	char *donaddress; // Donation address
+	bool donvalid; // Donation address works on this network
 
 	/* Stratum options */
 	server_instance_t **servers;
diff --git a/src/stratifier.c b/src/stratifier.c
index 1125a212..fe21ccef 100644
--- a/src/stratifier.c
+++ b/src/stratifier.c
@@ -34,7 +34,7 @@ static const char *scriptsig_header = "01000000010000000000000000000000000000000
 static uchar scriptsig_header_bin[41];
 
 static char pubkeytxnbin[25];
-static char pubkeytxn[52];
+static char donkeytxnbin[25];
 
 /* Add unaccounted shares when they arrive, remove them with each update of
  * rolling stats. */
@@ -281,9 +281,9 @@ static const char *ckdb_ids[] = {
 
 static void generate_coinbase(ckpool_t *ckp, workbase_t *wb)
 {
+	uint64_t *u64, g64, d64 = 0;
 	char header[228];
 	int len, ofs = 0;
-	uint64_t *u64;
 	ts_t now;
 
 	/* Strings in wb should have been zero memset prior. Generate binary
@@ -324,7 +324,7 @@ static void generate_coinbase(ckpool_t *ckp, workbase_t *wb)
 	len += wb->enonce1varlen;
 	len += wb->enonce2varlen;
 
-	wb->coinb2bin = ckzalloc(128);
+	wb->coinb2bin = ckzalloc(256);
 	memcpy(wb->coinb2bin, "\x0a\x63\x6b\x70\x6f\x6f\x6c", 7);
 	wb->coinb2len = 7;
 	if (ckp->btcsig) {
@@ -347,16 +347,33 @@ static void generate_coinbase(ckpool_t *ckp, workbase_t *wb)
 	memcpy(wb->coinb2bin + wb->coinb2len, "\xff\xff\xff\xff", 4);
 	wb->coinb2len += 4;
 
-	wb->coinb2bin[wb->coinb2len++] = 1;
+	// Generation value
+	g64 = wb->coinbasevalue;
+	if (ckp->donvalid) {
+		d64 = g64 / 200; // 0.5% donation
+		g64 -= d64; // To guarantee integers add up to the original coinbasevalue
+		wb->coinb2bin[wb->coinb2len++] = 2; // 2 transactions
+	} else
+		wb->coinb2bin[wb->coinb2len++] = 1; // 2 transactions
+
 	u64 = (uint64_t *)&wb->coinb2bin[wb->coinb2len];
-	*u64 = htole64(wb->coinbasevalue);
+	*u64 = htole64(g64);
 	wb->coinb2len += 8;
 
 	wb->coinb2bin[wb->coinb2len++] = 25;
-
 	memcpy(wb->coinb2bin + wb->coinb2len, pubkeytxnbin, 25);
 	wb->coinb2len += 25;
 
+	if (ckp->donvalid) {
+		u64 = (uint64_t *)&wb->coinb2bin[wb->coinb2len];
+		*u64 = htole64(d64);
+		wb->coinb2len += 8;
+
+		wb->coinb2bin[wb->coinb2len++] = 25;
+		memcpy(wb->coinb2bin + wb->coinb2len, donkeytxnbin, 25);
+		wb->coinb2len += 25;
+	}
+
 	wb->coinb2len += 4; // Blank lock
 
 	wb->coinb2 = bin2hex(wb->coinb2bin, wb->coinb2len);
@@ -1537,7 +1554,7 @@ test_blocksolve(stratum_instance_t *client, workbase_t *wb, const uchar *data, c
 		double diff, const char *coinbase, int cblen, const char *nonce2, const char *nonce)
 {
 	int transactions = wb->transactions + 1;
-	char hexcoinbase[512], blockhash[68];
+	char hexcoinbase[1024], blockhash[68];
 	char *gbt_block, varint[12];
 	json_t *val = NULL;
 	char cdfield[64];
@@ -1557,7 +1574,7 @@ test_blocksolve(stratum_instance_t *client, workbase_t *wb, const uchar *data, c
 	ts_realtime(&ts_now);
 	sprintf(cdfield, "%lu,%lu", ts_now.tv_sec, ts_now.tv_nsec);
 
-	gbt_block = ckalloc(512);
+	gbt_block = ckalloc(1024);
 	sprintf(gbt_block, "submitblock:");
 	__bin2hex(gbt_block + 12, data, 80);
 	if (transactions < 0xfd) {
@@ -2544,12 +2561,27 @@ static void *statsupdate(void *arg)
 	return NULL;
 }
 
+static bool test_address(ckpool_t *ckp, const char *address)
+{
+	bool ret = false;
+	char *buf, *msg;
+
+	ASPRINTF(&msg, "checkaddr:%s", address);
+	buf = send_recv_proc(ckp->generator, msg);
+	dealloc(msg);
+	if (!buf)
+		return ret;
+	ret = cmdmatch(buf, "true");
+	dealloc(buf);
+	return ret;
+}
+
 int stratifier(proc_instance_t *pi)
 {
 	pthread_t pth_blockupdate, pth_statsupdate;
 	ckpool_t *ckp = pi->ckp;
-	char *buf, *msg;
 	int ret = 1;
+	char *buf;
 
 	LOGWARNING("%s stratifier starting", ckp->name);
 
@@ -2562,23 +2594,19 @@ int stratifier(proc_instance_t *pi)
 		buf = send_recv_proc(ckp->generator, "ping");
 	} while (!buf);
 
-	ASPRINTF(&msg, "checkaddr:%s", ckp->btcaddress);
-	buf = send_recv_proc(ckp->generator, msg);
-	dealloc(msg);
-	if (!buf) {
-		LOGEMERG("Fatal: No response to checkaddr from generator");
-		goto out;
-	}
-	if (cmdmatch(buf, "false")) {
-		LOGEMERG("Fatal: btcaddress invalid accoring to bitcoind");
-		dealloc(buf);
+	if (!test_address(ckp, ckp->btcaddress)) {
+		LOGEMERG("Fatal: btcaddress invalid according to bitcoind");
 		goto out;
 	}
 
 	/* Store this for use elsewhere */
 	hex2bin(scriptsig_header_bin, scriptsig_header, 41);
 	address_to_pubkeytxn(pubkeytxnbin, ckp->btcaddress);
-	__bin2hex(pubkeytxn, pubkeytxnbin, 25);
+
+	if (test_address(ckp, ckp->donaddress)) {
+		ckp->donvalid = true;
+		address_to_pubkeytxn(donkeytxnbin, ckp->donaddress);
+	}
 
 	/* Set the initial id to time as high bits so as to not send the same
 	 * id on restarts */