diff --git a/blkmaker.c b/blkmaker.c
index 8a4cb77..8da534a 100644
--- a/blkmaker.c
+++ b/blkmaker.c
@@ -34,9 +34,16 @@ bool _blkmk_dblsha256(void *hash, const void *data, size_t datasz) {
 
 #define dblsha256 _blkmk_dblsha256
 
-uint64_t blkmk_init_generation(blktemplate_t *tmpl, void *script, size_t scriptsz) {
+uint64_t blkmk_init_generation2(blktemplate_t *tmpl, void *script, size_t scriptsz, bool *out_newcb) {
 	if (tmpl->cbtxn)
+	{
+		if (out_newcb)
+			*out_newcb = false;
 		return 0;
+	}
+	
+	if (out_newcb)
+		*out_newcb = true;
 	
 	size_t datasz = 62 + sizeof(blkheight_t) + scriptsz;
 	unsigned char *data = malloc(datasz);
@@ -94,6 +101,10 @@ uint64_t blkmk_init_generation(blktemplate_t *tmpl, void *script, size_t scripts
 	return tmpl->cbvalue;
 }
 
+uint64_t blkmk_init_generation(blktemplate_t *tmpl, void *script, size_t scriptsz) {
+	return blkmk_init_generation2(tmpl, script, scriptsz, NULL);
+}
+
 static
 bool build_merkle_root(unsigned char *mrklroot_out, blktemplate_t *tmpl, unsigned char *cbtxndata, size_t cbtxndatasz) {
 	size_t hashcount = tmpl->txncount + 1;
diff --git a/blkmaker.h b/blkmaker.h
index 6c1872c..5f4fb06 100644
--- a/blkmaker.h
+++ b/blkmaker.h
@@ -7,12 +7,13 @@
 
 #include <blktemplate.h>
 
-#define BLKMAKER_VERSION (2L)
+#define BLKMAKER_VERSION (3L)
 #define BLKMAKER_MAX_BLOCK_VERSION (2)
 
 extern bool (*blkmk_sha256_impl)(void *hash_out, const void *data, size_t datasz);
 
 extern uint64_t blkmk_init_generation(blktemplate_t *, void *script, size_t scriptsz);
+extern uint64_t blkmk_init_generation2(blktemplate_t *, void *script, size_t scriptsz, bool *out_newcb);
 extern ssize_t blkmk_append_coinbase_safe(blktemplate_t *, const void *append, size_t appendsz);
 extern bool _blkmk_extranonce(blktemplate_t *tmpl, void *vout, unsigned int workid, size_t *offs);
 extern size_t blkmk_get_data(blktemplate_t *, void *buf, size_t bufsz, time_t usetime, int16_t *out_expire, unsigned int *out_dataid);