diff --git a/src/core.c b/src/core.c
index 42618705..b907e402 100644
--- a/src/core.c
+++ b/src/core.c
@@ -4701,7 +4701,8 @@ static __inline void mdbx_meta_update_end(const MDBX_env *env, MDBX_meta *meta,
 
 static __inline void mdbx_meta_set_txnid(const MDBX_env *env, MDBX_meta *meta,
                                          txnid_t txnid) {
-  mdbx_assert(env, meta < METAPAGE(env, 0) || meta > METAPAGE_END(env));
+  mdbx_assert(env, !env->me_map || meta < METAPAGE(env, 0) ||
+                       meta >= METAPAGE_END(env));
   (void)env;
   /* update inconsistent since this function used ONLY for filling meta-image
    * for writing, but not the actual meta-page */
diff --git a/test/keygen.cc b/test/keygen.cc
index a941e3ae..183dd467 100644
--- a/test/keygen.cc
+++ b/test/keygen.cc
@@ -410,8 +410,8 @@ void __hot maker::mk_continue(const serial_t serial, const essentials &params,
   assert(out.value.iov_len <= params.maxlen);
   assert(out.value.iov_len >= length(serial));
   assert(out.value.iov_base >= out.bytes);
-  assert((uint8_t *)out.value.iov_base + out.value.iov_len <=
-         out.bytes + out.limit);
+  assert((char *)out.value.iov_base + out.value.iov_len <=
+         (char *)&out.bytes + out.limit);
 }
 
 void log_pair(logging::loglevel level, const char *prefix, const buffer &key,