diff --git a/src/sia.c b/src/sia.c
index 057202c..8863966 100644
--- a/src/sia.c
+++ b/src/sia.c
@@ -7,6 +7,7 @@
 #include <os_seed.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <format.h>
 #include <string.h>
 
 #include "blake2b.h"
@@ -64,12 +65,7 @@ void deriveAndSign(uint8_t *dst, uint32_t index, const uint8_t *hash) {
 }
 
 void bin2hex(char *dst, const uint8_t *data, uint64_t inlen) {
-    static uint8_t const hex[] = "0123456789abcdef";
-    for (uint64_t i = 0; i < inlen; i++) {
-        dst[2 * i + 0] = hex[(data[i] >> 4) & 0x0F];
-        dst[2 * i + 1] = hex[(data[i] >> 0) & 0x0F];
-    }
-    dst[2 * inlen] = '\0';
+    format_hex(data, inlen, dst, inlen * 2 + 1);
 }
 
 void pubkeyToSiaAddress(char *dst, const uint8_t publicKey[static 65]) {