diff --git a/test/nested.cc b/test/nested.cc
index beebd880..335b22bc 100644
--- a/test/nested.cc
+++ b/test/nested.cc
@@ -178,7 +178,6 @@ bool testcase_nested::trim_tail(unsigned window_width) {
                 fifo.size());
     db_table_clear(dbi, txn_guard.get());
     fifo.clear();
-    speculum.clear();
   }
   return true;
 }
diff --git a/test/test.cc b/test/test.cc
index 9da2cf2f..4cc4e286 100644
--- a/test/test.cc
+++ b/test/test.cc
@@ -172,6 +172,7 @@ void testcase::txn_begin(bool readonly, unsigned flags) {
   if (unlikely(rc != MDBX_SUCCESS))
     failure_perror("mdbx_txn_begin()", rc);
   txn_guard.reset(txn);
+  need_speculum_assign = config.params.speculum && !readonly;
 
   log_trace("<< txn_begin(%s, 0x%04X)", readonly ? "read-only" : "read-write",
             flags);
@@ -192,9 +193,12 @@ int testcase::breakable_commit() {
       if (unlikely(err != MDBX_SUCCESS && err != MDBX_THREAD_MISMATCH &&
                    err != MDBX_BAD_TXN))
         failure_perror("mdbx_txn_abort()", err);
+      if (need_speculum_assign)
+        speculum = speculum_commited;
     } else
       failure_perror("mdbx_txn_commit()", err);
-  }
+  } else if (need_speculum_assign)
+    speculum_commited = speculum;
 
   log_trace("<< txn_commit: %s", rc ? "failed" : "Ok");
   return rc;
@@ -224,11 +228,15 @@ void testcase::txn_end(bool abort) {
     if (unlikely(err != MDBX_SUCCESS && err != MDBX_THREAD_MISMATCH &&
                  err != MDBX_BAD_TXN))
       failure_perror("mdbx_txn_abort()", err);
+    if (need_speculum_assign)
+      speculum = speculum_commited;
   } else {
     txn_inject_writefault(txn);
     int err = mdbx_txn_commit(txn);
     if (unlikely(err != MDBX_SUCCESS))
       failure_perror("mdbx_txn_commit()", err);
+    if (need_speculum_assign)
+      speculum_commited = speculum;
   }
 
   log_trace("<< txn_end(%s)", abort ? "abort" : "commit");
@@ -491,6 +499,7 @@ void testcase::db_table_drop(MDBX_dbi handle) {
     int rc = mdbx_drop(txn_guard.get(), handle, true);
     if (unlikely(rc != MDBX_SUCCESS))
       failure_perror("mdbx_drop(delete=true)", rc);
+    speculum.clear();
     log_trace("<< testcase::db_table_drop");
   } else {
     log_trace("<< testcase::db_table_drop: not needed");
@@ -502,6 +511,7 @@ void testcase::db_table_clear(MDBX_dbi handle, MDBX_txn *txn) {
   int rc = mdbx_drop(txn ? txn : txn_guard.get(), handle, false);
   if (unlikely(rc != MDBX_SUCCESS))
     failure_perror("mdbx_drop(delete=false)", rc);
+  speculum.clear();
   log_trace("<< testcase::db_table_clear");
 }
 
diff --git a/test/test.h b/test/test.h
index 5024589e..8194b057 100644
--- a/test/test.h
+++ b/test/test.h
@@ -133,6 +133,9 @@ protected:
       return cmp < 0;
     }
   };
+
+  // for simplify the set<pair<key,value>>
+  // is used instead of multimap<key,value>
   using SET = std::set<Item, ItemCompare>;
 
   const actor_config &config;
@@ -143,6 +146,7 @@ protected:
   scoped_txn_guard txn_guard;
   scoped_cursor_guard cursor_guard;
   bool signalled{false};
+  bool need_speculum_assign{false};
 
   size_t nops_completed{0};
   chrono::time start_timestamp;
@@ -154,7 +158,7 @@ protected:
     mdbx_canary canary;
   } last;
 
-  SET speculum{ItemCompare(this)};
+  SET speculum{ItemCompare(this)}, speculum_commited{ItemCompare(this)};
   bool speculum_verify();
   int insert(const keygen::buffer &akey, const keygen::buffer &adata,
              unsigned flags);
@@ -233,11 +237,10 @@ public:
 
 class testcase_hill : public testcase {
   using inherited = testcase;
-  SET speculum_commited;
 
 public:
   testcase_hill(const actor_config &config, const mdbx_pid_t pid)
-      : testcase(config, pid), speculum_commited(ItemCompare(this)) {}
+      : testcase(config, pid) {}
   bool run() override;
 };
 
diff --git a/test/ttl.cc b/test/ttl.cc
index 92e99b82..a410d943 100644
--- a/test/ttl.cc
+++ b/test/ttl.cc
@@ -97,7 +97,7 @@ bool testcase_ttl::run() {
         for (unsigned n = 0; n < tail_count; ++n) {
           log_trace("ttl: remove-tail %" PRIu64, tail_serial);
           generate_pair(tail_serial);
-          err = mdbx_del(txn_guard.get(), dbi, &key->value, &data->value);
+          err = remove(key, data);
           if (unlikely(err != MDBX_SUCCESS)) {
             if (err == MDBX_MAP_FULL && config.params.ignore_dbfull) {
               log_notice("ttl: tail-bailout due '%s'", mdbx_strerror(err));
@@ -120,13 +120,17 @@ bool testcase_ttl::run() {
       log_notice("ttl: bailout at commit due '%s'", mdbx_strerror(err));
       break;
     }
+    if (!speculum_verify()) {
+      log_notice("ttl: bailout after tail-trim");
+      return false;
+    }
+
     fifo.push_front(std::make_pair(serial, head_count));
   retry:
     for (unsigned n = 0; n < head_count; ++n) {
       log_trace("ttl: insert-head %" PRIu64, serial);
       generate_pair(serial);
-      err = mdbx_put(txn_guard.get(), dbi, &key->value, &data->value,
-                     insert_flags);
+      err = insert(key, data, insert_flags);
       if (unlikely(err != MDBX_SUCCESS)) {
         if (err == MDBX_MAP_FULL && config.params.ignore_dbfull) {
           log_notice("ttl: head-insert skip due '%s'", mdbx_strerror(err));
@@ -149,6 +153,10 @@ bool testcase_ttl::run() {
       serial = fifo.front().first;
       fifo.pop_front();
     }
+    if (!speculum_verify()) {
+      log_notice("ttl: bailout after head-grow");
+      return false;
+    }
 
     report(1);
     rc = true;