diff --git a/chipset/realtek/btstack_chipset_realtek.c b/chipset/realtek/btstack_chipset_realtek.c
index de483dda3..e97bea888 100644
--- a/chipset/realtek/btstack_chipset_realtek.c
+++ b/chipset/realtek/btstack_chipset_realtek.c
@@ -280,7 +280,7 @@ static uint32_t read_file(FILE **file, uint8_t **buf, const char *name) {
     // read file
     size_t ret = fread(*buf, size, 1, *file);
     if (ret != 1) {
-        log_info("Failed to read %u bytes from file %s (ret = %u)", size, name, ret);
+        log_info("Failed to read %u bytes from file %s (ret = %d)", size, name, (int) ret);
         fclose(*file);
         free(*buf);
         *file = NULL;