diff --git a/runtime/flang/utils.c b/runtime/flang/utils.c
index 6cae64eca21..d57167ce8e0 100644
--- a/runtime/flang/utils.c
+++ b/runtime/flang/utils.c
@@ -604,38 +604,6 @@ __fortio_trunc(FIO_FCB *p, seekoffx_t length)
 }
 
 #ifdef _WIN32
-int
-__fortio_binary_mode(void *fp)
-{
-#if defined(WINNT)
-#include <fcntl.h>
-
-#if defined(WIN64) || defined(WIN32)
-#define O_BINARY _O_BINARY
-#endif
-
- int mode;
-
- mode = setmode(fileno((FILE *)fp), O_BINARY);
- if (mode == -1) {
-   /* The mode argument is clearly legal, so this should not
-    * happen.  But, in a console app, setmode will fail on
-    * the fd representing stdout.
-    */
-   return 0;
- }
- (void)setmode(fileno((FILE *)fp), mode);
- return (mode & O_BINARY);
-#else
- return 1;
-#endif
-}
-
-void
-__fortio_setmode_binary(FILE *f) {
-    _setmode(_fileno(f), _O_BINARY);
-}
-
 void
 sincos(double x, double *sine, double *cosine) {
     *sine = sin(x);
diff --git a/runtime/include/stdioInterf.h b/runtime/include/stdioInterf.h
index 4391ec8668f..ab7226ad6ae 100644
--- a/runtime/include/stdioInterf.h
+++ b/runtime/include/stdioInterf.h
@@ -24,6 +24,13 @@
 #endif
 #include <stdlib.h>
 
+/* for some reason these are not correctly defined on WIN32 */
+#ifdef _WIN32
+#define __fortio_setmode_binary __io_setmode_binary
+#define __fortio_binary_mode __io_binary_mode
+
+#endif
+
 /* defines to use real host stdio routines */
 
 #define __io_fclose(fp) fclose(fp)