diff --git a/test/long_stochastic.sh b/test/long_stochastic.sh
index a51d1f86..2e721101 100755
--- a/test/long_stochastic.sh
+++ b/test/long_stochastic.sh
@@ -176,7 +176,8 @@ function probe {
   echo "=============================================== $(date)"
   echo "${caption}: $*"
   rm -f ${TESTDB_DIR}/* \
-    && ${VALGRIND} ./mdbx_test --ignore-dbfull --repeat=3 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no "$@" | tee >(lz4 > ${TESTDB_DIR}/long.log.lz4) | grep -e reach -e achieve \
+    && ${VALGRIND} ./mdbx_test --speculum --ignore-dbfull --repeat=3 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no "$@" \
+      | tee >(lz4 > ${TESTDB_DIR}/long.log.lz4) | grep -e reach -e achieve \
     && ${VALGRIND} ./mdbx_chk ${TESTDB_DIR}/long.db | tee ${TESTDB_DIR}/long-chk.log \
     && ([ ! -e ${TESTDB_DIR}/long.db-copy ] || ${VALGRIND} ./mdbx_chk ${TESTDB_DIR}/long.db-copy | tee ${TESTDB_DIR}/long-chk-copy.log) \
     || (echo "FAILED"; exit 1)