2 files changed, 5 insertions, 7 deletions
diff --git a/perl.h b/perl.h
index 7d93332f0d..a3f63b0cce 100644
--- a/perl.h
+++ b/perl.h
@@ -140,15 +140,15 @@
 #    ifdef PERL_GLOBAL_STRUCT_PRIVATE
        EXTERN_C struct perl_vars* Perl_GetVarsPrivate();
 #      define PERL_GET_VARS() Perl_GetVarsPrivate() /* see miniperlmain.c */
-#      ifndef PERLIO_FUNCS_CONST
-#        define PERLIO_FUNCS_CONST /* Can't have these lying around. */
-#      endif
 #    else
 #      define PERL_GET_VARS() PL_VarsPtr
 #    endif
 #  endif
 #endif
 
+/* this used to be off by default, now its on, see perlio.h */
+#define PERLIO_FUNCS_CONST
+
 #define pVAR    struct perl_vars* my_vars PERL_UNUSED_DECL
 
 #ifdef PERL_GLOBAL_STRUCT
diff --git a/perlio.h b/perlio.h
index 777c886f3f..dc80d086f7 100644
--- a/perlio.h
+++ b/perlio.h
@@ -86,10 +86,8 @@ typedef PerlIOl *PerlIO;
 #define PerlIO PerlIO
 #define PERLIO_LAYERS 1
 
-/* Making the big PerlIO_funcs vtables const is good (enables placing
- * them in the const section which is good for speed, security, and
- * embeddability) but this cannot be done by default because of
- * backward compatibility. */
+/* PERLIO_FUNCS_CONST is now on by default for efficiency, PERLIO_FUNCS_CONST
+   can be removed 1 day once stable & then PerlIO vtables are permanently RO */
 #ifdef PERLIO_FUNCS_CONST
 #define PERLIO_FUNCS_DECL(funcs) const PerlIO_funcs funcs
 #define PERLIO_FUNCS_CAST(funcs) (PerlIO_funcs*)(funcs)