diff --git a/lldb/source/Host/common/Editline.cpp b/lldb/source/Host/common/Editline.cpp
index 6af5f38b5894d..0f3a90461f69e 100644
--- a/lldb/source/Host/common/Editline.cpp
+++ b/lldb/source/Host/common/Editline.cpp
@@ -1197,7 +1197,7 @@ Editline::Editline(const char *editline_name, FILE *input_file,
     if (term_fd != -1) {
       static std::mutex *g_init_terminal_fds_mutex_ptr = nullptr;
       static std::set<int> *g_init_terminal_fds_ptr = nullptr;
-      static std::once_flag g_once_flag;
+      static llvm::once_flag g_once_flag;
       llvm::call_once(g_once_flag, [&]() {
         g_init_terminal_fds_mutex_ptr =
             new std::mutex(); // NOTE: Leak to avoid C++ destructor chain issues
diff --git a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
index efc08033974c0..5d9a861ff16a9 100644
--- a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
+++ b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
@@ -863,7 +863,7 @@ static void LoadCoreMediaFormatters(TypeCategoryImplSP objc_category_sp) {
 }
 
 lldb::TypeCategoryImplSP ObjCLanguage::GetFormatters() {
-  static std::once_flag g_initialize;
+  static llvm::once_flag g_initialize;
   static TypeCategoryImplSP g_category;
 
   llvm::call_once(g_initialize, [this]() -> void {
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 9e66070b4cdf0..23ff55e542bfa 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -3593,7 +3593,7 @@ void ProcessGDBRemote::KillDebugserverProcess() {
 }
 
 void ProcessGDBRemote::Initialize() {
-  static std::once_flag g_once_flag;
+  static llvm::once_flag g_once_flag;
 
   llvm::call_once(g_once_flag, []() {
     PluginManager::RegisterPlugin(GetPluginNameStatic(),
diff --git a/lldb/source/Plugins/ScriptInterpreter/None/ScriptInterpreterNone.cpp b/lldb/source/Plugins/ScriptInterpreter/None/ScriptInterpreterNone.cpp
index a418587688c81..7b95983795530 100644
--- a/lldb/source/Plugins/ScriptInterpreter/None/ScriptInterpreterNone.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/None/ScriptInterpreterNone.cpp
@@ -39,7 +39,7 @@ void ScriptInterpreterNone::ExecuteInterpreterLoop() {
 }
 
 void ScriptInterpreterNone::Initialize() {
-  static std::once_flag g_once_flag;
+  static llvm::once_flag g_once_flag;
 
   llvm::call_once(g_once_flag, []() {
     PluginManager::RegisterPlugin(GetPluginNameStatic(),