diff --git a/cgminer.c b/cgminer.c
index 09e22928..9412d268 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -2303,13 +2303,11 @@ static bool submit_upstream_work(struct work *work, CURL *curl, bool resubmit)
 
 	/* build JSON-RPC request */
 	if (work->gbt) {
-		char *gbt_block, *varint, *header;
+		char *gbt_block, *varint;
 		unsigned char data[80];
 
 		flip80(data, work->data);
-		header = bin2hex(data, 80);
-		gbt_block = calloc_strcat(header);
-		free(header);
+		gbt_block = bin2hex(data, 80);
 
 		if (work->gbt_txns < 0xfd) {
 			uint8_t val = work->gbt_txns;
diff --git a/util.c b/util.c
index 8f17955f..82c0907e 100644
--- a/util.c
+++ b/util.c
@@ -1478,27 +1478,6 @@ void dev_error(struct cgpu_info *dev, enum dev_reason reason)
 
 }
 
-/* Calloc enough memory to fit string s, rounding up to 4 byte alignment */
-void *calloc_strcat(char *s)
-{
-	size_t len = strlen(s);
-	void *ptr = NULL;
-
-	if (!len)
-		goto out;
-
-	len += 1;
-	if (len % 4)
-		len += 4 - (len % 4);
-	ptr = calloc(len, 1);
-	if (unlikely(!ptr))
-		quit(1, "Failed to calloc ptr in calloc_str");
-
-	sprintf(ptr, "%s", s);
-out:
-	return ptr;
-}
-
 /* Realloc an existing string to fit an extra string s, appending s to it. */
 void *realloc_strcat(char *ptr, char *s)
 {
diff --git a/util.h b/util.h
index b28618c2..8411dd34 100644
--- a/util.h
+++ b/util.h
@@ -52,7 +52,6 @@ bool extract_sockaddr(struct pool *pool, char *url);
 bool auth_stratum(struct pool *pool);
 bool initiate_stratum(struct pool *pool);
 void dev_error(struct cgpu_info *dev, enum dev_reason reason);
-void *calloc_strcat(char *s);
 void *realloc_strcat(char *ptr, char *s);
 
 #endif /* __UTIL_H__ */