diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index 118adda3b3..f7d33233d8 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -1501,7 +1501,7 @@ static int mbedtls_init(void)
 #endif /* !MBEDTLS_CTR_DRBG_C && !MBEDTLS_HMAC_DRBG_C */
 
   if(ret != 0) {
-    /* TODO: write an error without a `data` param
+    /* FIXME: write an error without a `data` param
     failf(" failed\n  ! mbedtls_ctr_drbg_seed returned -0x%x\n",
                   (unsigned int)-ret);
     */