diff --git a/tdutils/td/utils/port/detail/PollableFd.h b/tdutils/td/utils/port/detail/PollableFd.h
index 06eddaa5a..9eebe921e 100644
--- a/tdutils/td/utils/port/detail/PollableFd.h
+++ b/tdutils/td/utils/port/detail/PollableFd.h
@@ -138,7 +138,7 @@ class PollableFdInfo : private ListNode {
 
  private:
   NativeFd fd_{};
-  std::atomic_flag lock_{false};
+  std::atomic_flag lock_ = ATOMIC_FLAG_INIT;
   PollFlagsSet flags_;
 #if TD_PORT_WINDOWS
   SpinLock observer_lock_;