diff --git a/wscript b/wscript
index c6f287ffa1..fa3d98d25e 100644
--- a/wscript
+++ b/wscript
@@ -227,6 +227,7 @@ iconv support use --disable-iconv.",
         'desc': 'posix_spawnp() or MinGW',
         'func': check_true,
         'deps_any': ['posix-spawn', 'mingw'],
+        'req': True,
     }, {
         'name': 'glob',
         'desc': 'glob()',