diff --git a/stratum/client_submit.cpp b/stratum/client_submit.cpp
index 11efebf..47dfd0f 100644
--- a/stratum/client_submit.cpp
+++ b/stratum/client_submit.cpp
@@ -406,8 +406,7 @@ bool client_submit(YAAMP_CLIENT *client, json_value *json_params)
 
 	YAAMP_JOB_TEMPLATE *templ = job->templ;
 
-	if(strlen(nonce) != YAAMP_NONCE_SIZE*2)
-	{
+	if(strlen(nonce) != YAAMP_NONCE_SIZE*2 || !ishexa(nonce, YAAMP_NONCE_SIZE*2)) {
 		client_submit_error(client, job, 20, "Invalid nonce size", extranonce2, ntime, nonce);
 		return true;
 	}
@@ -451,13 +450,11 @@ bool client_submit(YAAMP_CLIENT *client, json_value *json_params)
 		if (extranull) {
 			debuglog("extranonce %s is empty!, should be %s - %s\n", extranonce2, extra1_id, client->sock->ip);
 			client_submit_error(client, job, 27, "Invalid extranonce2 suffix", extranonce2, ntime, nonce);
-			client->submit_bad++;
 			return true;
 		}
 		if (extradiff) {
 			// some ccminer pre-release doesn't fill correctly the extranonce
 			client_submit_error(client, job, 27, "Invalid extranonce2 suffix", extranonce2, ntime, nonce);
-			client->submit_bad++;
 			socket_send(client->sock, "{\"id\":null,\"method\":\"mining.set_extranonce\",\"params\":[\"%s\",%d]}\n",
 				client->extranonce1, client->extranonce2size);
 			return true;
@@ -465,7 +462,6 @@ bool client_submit(YAAMP_CLIENT *client, json_value *json_params)
 	}
 	else if(!ishexa(extranonce2, client->extranonce2size*2)) {
 		client_submit_error(client, job, 27, "Invalid nonce2", extranonce2, ntime, nonce);
-		client->submit_bad++;
 		return true;
 	}