diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 2db13d30308..d2787b50beb 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -300,8 +300,12 @@ static OP  *pp_require_safe(pTHX);
 static void activate_interpreter(plperl_interp_desc *interp_desc);
 
 #ifdef WIN32
+#if PERL_VERSION >= 28
+#define setlocale_perl(a,b)  Perl_setlocale(a,b)
+#else
 static char *setlocale_perl(int category, char *locale);
 #endif
+#endif
 
 /*
  * Decrement the refcount of the given SV within the active Perl interpreter
@@ -4159,6 +4163,7 @@ plperl_inline_callback(void *arg)
  * (needed because of the calls to new_*())
  */
 #ifdef WIN32
+#if PERL_VERSION < 28
 static char *
 setlocale_perl(int category, char *locale)
 {
@@ -4226,5 +4231,6 @@ setlocale_perl(int category, char *locale)
 
 	return RETVAL;
 }
+#endif 							/* PERL_VERSION < 28 */
 
 #endif							/* WIN32 */
diff --git a/src/pl/plperl/plperl.h b/src/pl/plperl/plperl.h
index 3748158a86d..0044983ed1b 100644
--- a/src/pl/plperl/plperl.h
+++ b/src/pl/plperl/plperl.h
@@ -51,11 +51,11 @@
  */
 #ifdef _MSC_VER
 #define __inline__ inline
+#define __builtin_expect(a, b)  (a == b)
 #ifdef isnan
 #undef isnan
 #endif
 #endif
-
 /*
  * Regarding bool, both PostgreSQL and Perl might use stdbool.h or not,
  * depending on configuration.  If both agree, things are relatively harmless.