diff --git a/embed.fnc b/embed.fnc
index 1be2d19be381..c2abf5636514 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -2209,7 +2209,7 @@ ARdp	|OP *	|newGVREF	|I32 type				\
 ARdmp	|HV *	|newHV
 ARdp	|HV *	|newHVhv	|NULLOK HV *hv
 ARdp	|OP *	|newHVREF	|NN OP *o
-AMRbdp	|IO *	|newIO
+ARdmp	|IO *	|newIO
 ARdp	|OP *	|newLISTOP	|I32 type				\
 				|I32 flags				\
 				|NULLOK OP *first			\
diff --git a/embed.h b/embed.h
index eef2eabca3ca..8ec0b6ebf7b9 100644
--- a/embed.h
+++ b/embed.h
@@ -424,6 +424,7 @@
 # define newHV()                                Perl_newHV(aTHX)
 # define newHVREF(a)                            Perl_newHVREF(aTHX_ a)
 # define newHVhv(a)                             Perl_newHVhv(aTHX_ a)
+# define newIO()                                Perl_newIO(aTHX)
 # define newLISTOP(a,b,c,d)                     Perl_newLISTOP(aTHX_ a,b,c,d)
 # define newLISTOPn(a,...)                      Perl_newLISTOPn(aTHX_ a,__VA_ARGS__)
 # define newLOGOP(a,b,c,d)                      Perl_newLOGOP(aTHX_ a,b,c,d)
diff --git a/mathoms.c b/mathoms.c
index 80e8122c7a4d..f40aa314846b 100644
--- a/mathoms.c
+++ b/mathoms.c
@@ -135,12 +135,6 @@ Perl_sv_nounlocking(pTHX_ SV *sv)
     PERL_UNUSED_ARG(sv);
 }
 
-IO *
-Perl_newIO(pTHX)
-{
-    return MUTABLE_IO(newSV_type(SVt_PVIO));
-}
-
 I32
 Perl_my_stat(pTHX)
 {
diff --git a/proto.h b/proto.h
index 462a298a9ae4..20fcc3004ea3 100644
--- a/proto.h
+++ b/proto.h
@@ -2906,6 +2906,10 @@ Perl_newHVhv(pTHX_ HV *hv)
         __attribute__warn_unused_result__;
 #define PERL_ARGS_ASSERT_NEWHVHV
 
+/* PERL_CALLCONV IO *
+Perl_newIO(pTHX)
+        __attribute__warn_unused_result__; */
+
 PERL_CALLCONV OP *
 Perl_newLISTOP(pTHX_ I32 type, I32 flags, OP *first, OP *last)
         __attribute__warn_unused_result__;
@@ -5905,11 +5909,6 @@ Perl_is_utf8_char_buf(const U8 *buf, const U8 *buf_end);
 # define PERL_ARGS_ASSERT_IS_UTF8_CHAR_BUF      \
         assert(buf); assert(buf_end)
 
-PERL_CALLCONV IO *
-Perl_newIO(pTHX)
-        __attribute__warn_unused_result__;
-# define PERL_ARGS_ASSERT_NEWIO
-
 PERL_CALLCONV CV *
 Perl_newSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *block);
 # define PERL_ARGS_ASSERT_NEWSUB
diff --git a/sv.h b/sv.h
index da5ac0764dfb..9dab94e7ea3e 100644
--- a/sv.h
+++ b/sv.h
@@ -2731,7 +2731,7 @@ Create a new IO, setting the reference count to 1.
 
 =cut
 */
-#define newIO()	MUTABLE_IO(newSV_type(SVt_PVIO))
+#define Perl_newIO(mTHX)  MUTABLE_IO(Perl_newSV_type(aTHX_ SVt_PVIO))
 
 #if defined(PERL_CORE) || defined(PERL_EXT)