1 files changed, 4 insertions, 0 deletions
diff --git a/perl.h b/perl.h
index d453cb6370..4436d1a5f4 100644
--- a/perl.h
+++ b/perl.h
@@ -4163,6 +4163,10 @@ extern void moncontrol(int);
 #define UNICODE_PARA_SEPA_1	0x80
 #define UNICODE_PARA_SEPA_2	0xA9
 
+#ifndef PIPESOCK_MODE
+#  define PIPESOCK_MODE
+#endif
+
 /* and finally... */
 #define PERL_PATCHLEVEL_H_IMPLICIT
 #include "patchlevel.h"