diff --git a/lib/curl_threads.c b/lib/curl_threads.c
index 24561a6dde..ed1ad30e73 100644
--- a/lib/curl_threads.c
+++ b/lib/curl_threads.c
@@ -142,8 +142,7 @@ void Curl_thread_destroy(curl_thread_t *hnd)
 
 int Curl_thread_join(curl_thread_t *hnd)
 {
-#if !defined(_WIN32_WINNT) || !defined(_WIN32_WINNT_VISTA) || \
-    (_WIN32_WINNT < _WIN32_WINNT_VISTA)
+#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < _WIN32_WINNT_VISTA)
   int ret = (WaitForSingleObject(*hnd, INFINITE) == WAIT_OBJECT_0);
 #else
   int ret = (WaitForSingleObjectEx(*hnd, INFINITE, FALSE) == WAIT_OBJECT_0);
diff --git a/lib/curl_threads.h b/lib/curl_threads.h
index fb74561ffa..3428fcd968 100644
--- a/lib/curl_threads.h
+++ b/lib/curl_threads.h
@@ -39,8 +39,7 @@
 #  define curl_mutex_t           CRITICAL_SECTION
 #  define curl_thread_t          HANDLE
 #  define curl_thread_t_null     (HANDLE)0
-#  if !defined(_WIN32_WINNT) || !defined(_WIN32_WINNT_VISTA) || \
-      (_WIN32_WINNT < _WIN32_WINNT_VISTA)
+#  if !defined(_WIN32_WINNT) || (_WIN32_WINNT < _WIN32_WINNT_VISTA)
 #    define Curl_mutex_init(m)   InitializeCriticalSection(m)
 #  else
 #    define Curl_mutex_init(m)   InitializeCriticalSectionEx(m, 0, 1)