diff --git a/perl.c b/perl.c
index d273a31eb8..e9e5b331ba 100644
--- a/perl.c
+++ b/perl.c
@@ -2597,7 +2597,7 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 
     if (xsinit)
         (*xsinit)(aTHX);	/* in case linked C routines want magical variables */
-#if defined(VMS) || defined(WIN32) || defined(__CYGWIN__)
+#if defined(VMS) || defined(WIN32) || defined(__CYGWIN__) || defined(__MVS__)
     init_os_extras();
 #endif
 
diff --git a/perl.h b/perl.h
index 1966fcf466..9cabb503a4 100644
--- a/perl.h
+++ b/perl.h
@@ -4469,7 +4469,7 @@ intrinsic function, see its documents for more details.
             cBOOL(PerlLIO_setmode(fileno(fp), mode) != -1)
 #endif
 
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__MVS__)
 void init_os_extras(void);
 #endif