diff --git a/benchmark/hardware.sh b/benchmark/hardware.sh
index 040f9169101192ce36417ab92a76a8478f049855..90e0e7dadfab7b0e6f92eb6387453f335e6decb8 100755
--- a/benchmark/hardware.sh
+++ b/benchmark/hardware.sh
@@ -14,6 +14,8 @@ TRIES=3
 AMD64_BIN_URL="https://clickhouse-builds.s3.yandex.net/0/e29c4c3cc47ab2a6c4516486c1b77d57e7d42643/clickhouse_build_check/gcc-10_relwithdebuginfo_none_bundled_unsplitted_disable_False_binary/clickhouse"
 AARCH64_BIN_URL="https://clickhouse-builds.s3.yandex.net/0/e29c4c3cc47ab2a6c4516486c1b77d57e7d42643/clickhouse_special_build_check/clang-10-aarch64_relwithdebuginfo_none_bundled_unsplitted_disable_False_binary/clickhouse"
 
+# Note: on older Ubuntu versions, 'axel' does not support IPv6. If you are using IPv6-only servers on very old Ubuntu, just don't install 'axel'.
+
 FASTER_DOWNLOAD=wget
 if command -v axel >/dev/null; then
     FASTER_DOWNLOAD=axel