diff --git a/BUILD.gn b/BUILD.gn
index dbcb091..fc1dbcc 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -120,6 +120,9 @@
   deps = [
     "//zircon/public/lib/fdio",
   ]
+  public_deps = [
+    "//zircon/public/fidl/fuchsia-hardware-pty:fuchsia-hardware-pty_c",
+  ]
 }
 
 package("vim") {
diff --git a/src/os_fuchsia.c b/src/os_fuchsia.c
index 5a39020..07d73b0 100644
--- a/src/os_fuchsia.c
+++ b/src/os_fuchsia.c
@@ -10,7 +10,8 @@
 
 #include "vim.h"
 
-#include <zircon/device/pty.h>
+#include <fuchsia/hardware/pty/c/fidl.h>
+#include <lib/fdio/unsafe.h>
 
 /*
  * Get the current window size in Rows and Columns.
@@ -18,13 +19,21 @@
     int
 mch_get_shellsize(void)
 {
-    pty_window_size_t wsz;
-    ssize_t r = ioctl_pty_get_window_size(0, &wsz);
-    if (r != sizeof(wsz)) {
+    if (!isatty(STDIN_FILENO)) {
         return -1;
     }
-    Columns = wsz.width;
-    Rows = wsz.height;
+
+    fdio_t* io = fdio_unsafe_fd_to_io(STDIN_FILENO);
+    fuchsia_hardware_pty_WindowSize wsz;
+    zx_status_t status;
+    zx_status_t call_status = fuchsia_hardware_pty_DeviceGetWindowSize(
+        fdio_unsafe_borrow_channel(io), &status, &wsz);
+    fdio_unsafe_release(io);
+    if (call_status != ZX_OK || status != ZX_OK) {
+        return -1;
+    }
+    Columns = wsz.height;
+    Rows = wsz.width;
     return OK;
 }