diff --git a/test/test.cc b/test/test.cc
index d955f25c..f32befd7 100644
--- a/test/test.cc
+++ b/test/test.cc
@@ -654,10 +654,13 @@ int testcase::remove(const keygen::buffer &akey, const keygen::buffer &adata) {
   return mdbx_del(txn_guard.get(), dbi, &akey->value, &adata->value);
 }
 
-bool testcase::speculum_verify() const {
+bool testcase::speculum_verify() {
   if (!config.params.speculum)
     return true;
 
+  if (!txn_guard)
+    txn_begin(true);
+
   char dump_key[128], dump_value[128];
   char dump_mkey[128], dump_mvalue[128];
 
diff --git a/test/test.h b/test/test.h
index 178100e1..3be05c11 100644
--- a/test/test.h
+++ b/test/test.h
@@ -153,7 +153,7 @@ protected:
   } last;
 
   SET speculum;
-  bool speculum_verify() const;
+  bool speculum_verify();
   int insert(const keygen::buffer &akey, const keygen::buffer &adata,
              unsigned flags);
   int replace(const keygen::buffer &akey, const keygen::buffer &new_value,