diff --git a/client/src/cmdhfksx6924.c b/client/src/cmdhfksx6924.c
index 10ec08e47..ab6888ac1 100644
--- a/client/src/cmdhfksx6924.c
+++ b/client/src/cmdhfksx6924.c
@@ -42,7 +42,7 @@
 
 static int CmdHelp(const char *Cmd);
 
-static void getAndPrintBalance() {
+static void getAndPrintBalance(void) {
     uint32_t balance;
     bool ret = KSX6924GetBalance(&balance);
     if (!ret) {