diff --git a/cpu-miner.c b/cpu-miner.c
index e1d8a5d..a47d77a 100644
--- a/cpu-miner.c
+++ b/cpu-miner.c
@@ -179,7 +179,7 @@ static void submit_work(struct work *work)
 {
 	char *hexstr = NULL;
 	json_t *val, *res;
-	char s[256];
+	char s[345];
 
 	printf("PROOF OF WORK FOUND?  submitting...\n");