diff --git a/components/bt/common/osi/config.c b/components/bt/common/osi/config.c
index c1d9a8ad5..b1dcfeca5 100644
--- a/components/bt/common/osi/config.c
+++ b/components/bt/common/osi/config.c
@@ -440,8 +440,9 @@ bool config_save(const config_t *config, const char *filename)
             goto error;
         }
     }else {
-        uint count = (w_cnt_total / CONFIG_FILE_MAX_SIZE);
-        for (int i = 0; i <= count; i++)
+        int count = (w_cnt_total / CONFIG_FILE_MAX_SIZE);
+        assert(count <= 0xFF);
+        for (uint8_t i = 0; i <= count; i++)
         {
             snprintf(keyname, keyname_bufsz, "%s%d", CONFIG_KEY, i);
             if (i == count) {