diff --git a/tdutils/td/utils/port/detail/ThreadStl.h b/tdutils/td/utils/port/detail/ThreadStl.h
index ce6ac27fe..dd55a21ec 100644
--- a/tdutils/td/utils/port/detail/ThreadStl.h
+++ b/tdutils/td/utils/port/detail/ThreadStl.h
@@ -12,6 +12,9 @@
 
 #include "td/utils/common.h"
 #include "td/utils/invoke.h"
+#if TD_WINDOWS
+#include "td/utils/port/detail/NativeFd.h"
+#endif
 #include "td/utils/port/detail/ThreadIdGuard.h"
 #include "td/utils/port/thread_local.h"
 #include "td/utils/Slice.h"
@@ -67,7 +70,7 @@ class ThreadStl {
   }
 
 #if TD_WINDOWS
-  using id = HANDLE;
+  using id = DWORD;
 #else
   using id = std::thread::id;
 #endif
@@ -81,7 +84,12 @@ class ThreadStl {
     if (static_cast<DWORD_PTR>(mask) != mask) {
       return Status::Error("Invalid thread affinity mask specified");
     }
-    if (SetThreadAffinityMask(thread_id, static_cast<DWORD_PTR>(mask))) {
+    auto handle = OpenThread(THREAD_SET_LIMITED_INFORMATION | THREAD_QUERY_LIMITED_INFORMATION, FALSE, thread_id);
+    if (handle == nullptr) {
+      return Status::Error("Failed to access thread");
+    }
+    NativeFd thread_handle(handle);
+    if (SetThreadAffinityMask(thread_handle.fd(), static_cast<DWORD_PTR>(mask))) {
       return Status::OK();
     }
     return OS_ERROR("Failed to set thread affinity mask");
@@ -95,9 +103,14 @@ class ThreadStl {
     DWORD_PTR process_mask = 0;
     DWORD_PTR system_mask = 0;
     if (GetProcessAffinityMask(GetCurrentProcess(), &process_mask, &system_mask)) {
-      auto result = SetThreadAffinityMask(thread_id, process_mask);
+      auto handle = OpenThread(THREAD_SET_LIMITED_INFORMATION | THREAD_QUERY_LIMITED_INFORMATION, FALSE, thread_id);
+      if (handle == nullptr) {
+        return 0;
+      }
+      NativeFd thread_handle(handle);
+      auto result = SetThreadAffinityMask(thread_handle.fd(), process_mask);
       if (result != 0 && result != process_mask) {
-        SetThreadAffinityMask(thread_id, result);
+        SetThreadAffinityMask(thread_handle.fd(), result);
       }
       return result;
     }
@@ -117,7 +130,7 @@ class ThreadStl {
 namespace this_thread_stl {
 #if TD_WINDOWS
 inline ThreadStl::id get_id() {
-  return GetCurrentThread();
+  return GetCurrentThreadId();
 }
 #else
 using std::this_thread::get_id;
diff --git a/tdutils/test/port.cpp b/tdutils/test/port.cpp
index 79a41596c..9287dae0b 100644
--- a/tdutils/test/port.cpp
+++ b/tdutils/test/port.cpp
@@ -289,19 +289,20 @@ TEST(Port, EventFdAndSignals) {
 TEST(Port, ThreadAffinityMask) {
   auto thread_id = td::this_thread::get_id();
   auto old_mask = td::thread::get_affinity_mask(thread_id);
-  LOG(INFO) << "Initial thread affinity mask: " << old_mask;
+  LOG(INFO) << "Initial thread " << thread_id << " affinity mask: " << old_mask;
   for (size_t i = 0; i < 64; i++) {
     auto mask = td::thread::get_affinity_mask(thread_id);
     LOG(INFO) << mask;
     auto result = td::thread::set_affinity_mask(thread_id, static_cast<td::uint64>(1) << i);
-    LOG(INFO) << i << ": " << result;
-    mask = td::thread::get_affinity_mask(thread_id);
-    LOG(INFO) << mask;
+    LOG(INFO) << i << ": " << result << ' ' << td::thread::get_affinity_mask(thread_id);
 
     if (i <= 1) {
       td::thread thread([] {
-        auto mask = td::thread::get_affinity_mask(td::this_thread::get_id());
-        LOG(INFO) << "New thread affinity mask: " << mask;
+        auto thread_id = td::this_thread::get_id();
+        auto mask = td::thread::get_affinity_mask(thread_id);
+        LOG(INFO) << "New thread " << thread_id << " affinity mask: " << mask;
+        auto result = td::thread::set_affinity_mask(thread_id, 1);
+        LOG(INFO) << "Thread " << thread_id << ": " << result << ' ' << td::thread::get_affinity_mask(thread_id);
       });
     }
   }