diff --git a/src/core.c b/src/core.c
index a3fe4842..13a02338 100644
--- a/src/core.c
+++ b/src/core.c
@@ -8152,13 +8152,17 @@ static __always_inline int check_txn(const MDBX_txn *txn, int bad_bits) {
   if (unlikely(txn->mt_flags & bad_bits))
     return MDBX_BAD_TXN;
 
+  mdbx_tassert(txn, (txn->mt_flags & MDBX_NOTLS) ==
+                        ((txn->mt_flags & MDBX_TXN_RDONLY)
+                             ? txn->mt_env->me_flags & MDBX_NOTLS
+                             : 0));
 #if MDBX_TXN_CHECKOWNER
-  if ((txn->mt_flags & MDBX_NOTLS) == 0 &&
-      unlikely(txn->mt_owner != mdbx_thread_self()))
+  if (unlikely(txn->mt_owner != mdbx_thread_self()) &&
+      (txn->mt_flags & (MDBX_NOTLS | MDBX_TXN_FINISHED)) == 0)
     return txn->mt_owner ? MDBX_THREAD_MISMATCH : MDBX_BAD_TXN;
 #endif /* MDBX_TXN_CHECKOWNER */
 
-  if (unlikely(!txn->mt_env->me_map))
+  if (bad_bits && unlikely(!txn->mt_env->me_map))
     return MDBX_EPERM;
 
   return MDBX_SUCCESS;