diff --git a/src/dwarfs/block_cache.cpp b/src/dwarfs/block_cache.cpp
index f13cc55b..8be1e722 100644
--- a/src/dwarfs/block_cache.cpp
+++ b/src/dwarfs/block_cache.cpp
@@ -42,6 +42,7 @@
 
 #include <folly/container/EvictingCacheMap.h>
 #include <folly/container/F14Map.h>
+#include <folly/system/HardwareConcurrency.h>
 #include <folly/system/ThreadName.h>
 
 #include "dwarfs/block_cache.h"
@@ -232,11 +233,11 @@ class block_cache_ final : public block_cache::impl {
       , LOG_PROXY_INIT(lgr)
       , options_(options) {
     if (options.init_workers) {
-      wg_ = worker_group("blkcache",
-                         std::max(options.num_workers > 0
-                                      ? options.num_workers
-                                      : std::thread::hardware_concurrency(),
-                                  static_cast<size_t>(1)));
+      wg_ =
+          worker_group("blkcache", std::max(options.num_workers > 0
+                                                ? options.num_workers
+                                                : folly::hardware_concurrency(),
+                                            static_cast<size_t>(1)));
     }
   }
 
diff --git a/src/dwarfsck.cpp b/src/dwarfsck.cpp
index 5e4c981a..5d330c5f 100644
--- a/src/dwarfsck.cpp
+++ b/src/dwarfsck.cpp
@@ -29,6 +29,7 @@
 #include <folly/FileUtil.h>
 #include <folly/String.h>
 #include <folly/json.h>
+#include <folly/system/HardwareConcurrency.h>
 
 #include "dwarfs/error.h"
 #include "dwarfs/filesystem_v2.h"
@@ -42,7 +43,7 @@ namespace dwarfs {
 namespace po = boost::program_options;
 
 int dwarfsck(int argc, char** argv) {
-  const size_t num_cpu = std::max(std::thread::hardware_concurrency(), 1u);
+  const size_t num_cpu = std::max(folly::hardware_concurrency(), 1u);
 
   std::string log_level, input, export_metadata, image_offset;
   size_t num_workers;
diff --git a/src/mkdwarfs.cpp b/src/mkdwarfs.cpp
index 3d56c3e6..9734dcbe 100644
--- a/src/mkdwarfs.cpp
+++ b/src/mkdwarfs.cpp
@@ -49,6 +49,7 @@
 #include <folly/Conv.h>
 #include <folly/FileUtil.h>
 #include <folly/gen/String.h>
+#include <folly/system/HardwareConcurrency.h>
 
 #include <fmt/format.h>
 
@@ -368,7 +369,7 @@ constexpr unsigned default_level = 7;
 int mkdwarfs(int argc, char** argv) {
   using namespace folly::gen;
 
-  const size_t num_cpu = std::max(std::thread::hardware_concurrency(), 1u);
+  const size_t num_cpu = std::max(folly::hardware_concurrency(), 1u);
 
   block_manager::config cfg;
   std::string path, output, memory_limit, script_arg, compression, header,