diff --git a/system/ulib/fdio/include/lib/fdio/io.h b/system/ulib/fdio/include/lib/fdio/io.h
index a4484ad51c887efb38cb3d24e50e438994bed08e..8209ceb9b05232f1759c18e51f78a9cb394076b3 100644
--- a/system/ulib/fdio/include/lib/fdio/io.h
+++ b/system/ulib/fdio/include/lib/fdio/io.h
@@ -19,8 +19,6 @@
 // and be used for all of stdio
 #define FDIO_FLAG_USE_FOR_STDIO 0x8000
 
-#define FDIO_NONBLOCKING 1
-
 // events for fdio_wait_fd()
 #define FDIO_EVT_READABLE POLLIN
 #define FDIO_EVT_WRITABLE POLLOUT
diff --git a/system/ulib/fdio/include/lib/fdio/vfs.h b/system/ulib/fdio/include/lib/fdio/vfs.h
index 4b3c6ff10c4d2302eae2c12d5abaf4aa9e1d0bcf..f32ccb1596ee1387fbb371f8a1c371b1622cbdbd 100644
--- a/system/ulib/fdio/include/lib/fdio/vfs.h
+++ b/system/ulib/fdio/include/lib/fdio/vfs.h
@@ -13,8 +13,6 @@
 
 __BEGIN_CDECLS
 
-#define VFS_MAX_HANDLES 2
-
 // On Fuchsia, the Block Device is transmitted by file descriptor, rather than
 // by path. This can prevent some racy behavior relating to FS start-up.
 #ifdef __Fuchsia__