diff --git a/configure.ac b/configure.ac
index 2d04f91051..9892250dd5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2834,8 +2834,7 @@ AS_HELP_STRING([--without-winidn], [disable Windows native IDN]),
       AC_LANG_PROGRAM([[
         #include <windows.h>
       ]],[[
-        #if (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x600) && \
-          (!defined(WINVER) || WINVER < 0x600)
+        #if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x600
         WINBASEAPI int WINAPI IdnToUnicode(DWORD dwFlags,
                                            const WCHAR *lpASCIICharStr,
                                            int cchASCIIChar,