diff --git a/client/TracyProfiler.cpp b/client/TracyProfiler.cpp
index b7a42c6f..f1cec8d4 100644
--- a/client/TracyProfiler.cpp
+++ b/client/TracyProfiler.cpp
@@ -74,9 +74,6 @@
 #if defined _WIN32 || defined __CYGWIN__
 #  include <lmcons.h>
 extern "C" typedef LONG (WINAPI *t_RtlGetVersion)( PRTL_OSVERSIONINFOW );
-#  if _WIN32_WINNT >= _WIN32_WINNT_VISTA
-#    define TRACY_USE_INIT_ONCE
-#  endif
 #else
 #  include <unistd.h>
 #  include <limits.h>
@@ -87,7 +84,6 @@ extern "C" typedef LONG (WINAPI *t_RtlGetVersion)( PRTL_OSVERSIONINFOW );
 #if defined __linux__
 #  include <sys/sysinfo.h>
 #  include <sys/utsname.h>
-#  define TRACY_USE_INIT_ONCE
 #endif
 
 #if !defined _WIN32 && !defined __CYGWIN__ && ( defined __i386 || defined _M_IX86 || defined __x86_64__ || defined _M_X64 )
@@ -98,50 +94,44 @@ namespace tracy
 {
 
 #ifndef TRACY_DELAYED_INIT
-#  if defined TRACY_USE_INIT_ONCE
-#    if defined _WIN32 || defined __CYGWIN__
 namespace
 {
-    BOOL CALLBACK InitOnceCallback(
-        PINIT_ONCE /*initOnce*/,
-        PVOID /*Parameter*/,
-        PVOID* /*Context*/)
+#  if ( defined _WIN32 || defined __CYGWIN__ ) && _WIN32_WINNT >= _WIN32_WINNT_VISTA
+    BOOL CALLBACK InitOnceCallback( PINIT_ONCE /*initOnce*/, PVOID /*Parameter*/, PVOID* /*Context*/)
     {
         rpmalloc_initialize();
         return TRUE;
     }
-
     INIT_ONCE InitOnce = INIT_ONCE_STATIC_INIT;
-}
-#    elif defined __linux__
-namespace
-{
+#  elif defined __linux__
     void InitOnceCallback()
     {
         rpmalloc_initialize();
     }
-
     pthread_once_t once_control = PTHREAD_ONCE_INIT;
+#  else
+    void InitOnceCallback()
+    {
+        rpmalloc_initialize();
+    }
+    std::once_flag once_flag;
+#  endif
 }
-#    endif
-#  endif //if defined TRACY_USE_INIT_ONCE
 
 struct RPMallocInit
 {
     RPMallocInit()
     {
-#  if defined TRACY_USE_INIT_ONCE
-#    if defined _WIN32 || defined __CYGWIN__
+#  if ( defined _WIN32 || defined __CYGWIN__ ) && _WIN32_WINNT >= _WIN32_WINNT_VISTA
         InitOnceExecuteOnce( &InitOnce, InitOnceCallback, nullptr, nullptr );
-#    elif defined __linux__
+#  elif defined __linux__
         pthread_once( &once_control, InitOnceCallback );
-#    endif
+#  else
+        std::call_once( once_flag, InitOnceCallback );
+#  endif
         // We must call rpmalloc_thread_initialize() explicitly here since the InitOnceCallback might
         // not be called on this thread if another thread has executed it earlier.
         rpmalloc_thread_initialize();
-#  else
-        rpmalloc_initialize();
-#  endif //if defined TRACY_USE_INIT_ONCE
     }
 };
 
@@ -149,13 +139,13 @@ struct RPMallocThreadInit
 {
     RPMallocThreadInit()
     {
-#  if defined TRACY_USE_INIT_ONCE
-#    if defined _WIN32 || defined __CYGWIN__
+#  if ( defined _WIN32 || defined __CYGWIN__ ) && _WIN32_WINNT >= _WIN32_WINNT_VISTA
         InitOnceExecuteOnce( &InitOnce, InitOnceCallback, nullptr, nullptr );
-#    else
+#  elif defined __linux__
         pthread_once( &once_control, InitOnceCallback );
-#    endif
-#  endif //if defined TRACY_USE_INIT_ONCE
+#  else
+        std::call_once( once_flag, InitOnceCallback );
+#  endif
         rpmalloc_thread_initialize();
     }
 };