diff --git a/dist/IO/IO.xs b/dist/IO/IO.xs
index db78f4d9f0a9..381488347248 100644
--- a/dist/IO/IO.xs
+++ b/dist/IO/IO.xs
@@ -56,10 +56,6 @@ typedef FILE * OutputStream;
 # define NORETURN_FUNCTION_END /* NOT REACHED */ return 0
 #endif
 
-#ifndef OpSIBLING
-#  define OpSIBLING(o) (o)->op_sibling
-#endif
-
 static int not_here(const char *s) __attribute__noreturn__;
 static int
 not_here(const char *s)
@@ -68,10 +64,6 @@ not_here(const char *s)
     NORETURN_FUNCTION_END;
 }
 
-#ifndef PerlIO
-#define PerlIO_fileno(f) fileno(f)
-#endif
-
 static int
 io_blocking(pTHX_ InputStream f, int block)
 {