1 files changed, 1 insertions, 0 deletions

diff --git a/perlio.c b/perlio.c
index e1f4353a9b..a71acba783 100644
--- a/perlio.c
+++ b/perlio.c
@@ -21,6 +21,7 @@
  */
 
 #include "EXTERN.h"
+#define PERL_IN_PERLIO_C
 #include "perl.h"
 
 #ifdef PERLIO_IS_STDIO