3 files changed, 11 insertions, 1 deletions
diff --git a/py/mpconfig.h b/py/mpconfig.h
index edf6e71d0e..890e072ab5 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -522,6 +522,12 @@ typedef double mp_float_t;
 #define MICROPY_STREAMS_NON_BLOCK (0)
 #endif
 
+// Whether to provide stream functions with POSIX-like signatures
+// (useful for porting existing libraries to MicroPython).
+#ifndef MICROPY_STREAMS_POSIX_API
+#define MICROPY_STREAMS_POSIX_API (0)
+#endif
+
 // Whether to call __init__ when importing builtin modules for the first time
 #ifndef MICROPY_MODULE_BUILTIN_INIT
 #define MICROPY_MODULE_BUILTIN_INIT (0)
diff --git a/py/stream.c b/py/stream.c
index d426973e83..473eb96904 100644
--- a/py/stream.c
+++ b/py/stream.c
@@ -511,6 +511,7 @@ STATIC mp_obj_t stream_ioctl(size_t n_args, const mp_obj_t *args) {
 }
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_ioctl_obj, 2, 3, stream_ioctl);
 
+#if MICROPY_STREAMS_POSIX_API
 /*
  * POSIX-like functions
  *
@@ -519,7 +520,6 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_stream_ioctl_obj, 2, 3, stream_ioctl);
  * POSIX-compatible software to work with MicroPython streams.
  */
 
-
 // errno-like variable. If any of the functions below returned with error
 // status, this variable will contain error no.
 int mp_stream_errno;
@@ -568,3 +568,5 @@ int mp_stream_posix_fsync(mp_obj_t stream) {
     }
     return res;
 }
+
+#endif
diff --git a/py/stream.h b/py/stream.h
index 8dd6898873..33d85e823c 100644
--- a/py/stream.h
+++ b/py/stream.h
@@ -84,11 +84,13 @@ mp_uint_t mp_stream_rw(mp_obj_t stream, void *buf, mp_uint_t size, int *errcode,
 
 void mp_stream_write_adaptor(void *self, const char *buf, size_t len);
 
+#if MICROPY_STREAMS_POSIX_API
 // Functions with POSIX-compatible signatures
 ssize_t mp_stream_posix_write(mp_obj_t stream, const void *buf, size_t len);
 ssize_t mp_stream_posix_read(mp_obj_t stream, void *buf, size_t len);
 off_t mp_stream_posix_lseek(mp_obj_t stream, off_t offset, int whence);
 int mp_stream_posix_fsync(mp_obj_t stream);
+#endif
 
 #if MICROPY_STREAMS_NON_BLOCK
 #define mp_is_nonblocking_error(errno) ((errno) == EAGAIN || (errno) == EWOULDBLOCK)