1 files changed, 1 insertions, 1 deletions
diff --git a/perlio.c b/perlio.c
index aa85c16f8c..6e3f4cffab 100644
--- a/perlio.c
+++ b/perlio.c
@@ -42,7 +42,7 @@
 #define PERL_IN_PERLIO_C
 #include "perl.h"
 
-#ifdef PERL_IMPLICIT_CONTEXT
+#ifdef MULTIPLICITY
 #  undef dSYS
 #  define dSYS dTHX
 #endif