diff --git a/src/unix/tty.c b/src/unix/tty.c
index e7c520f7..2385911c 100644
--- a/src/unix/tty.c
+++ b/src/unix/tty.c
@@ -293,7 +293,14 @@ uv_handle_type uv_guess_handle(uv_file file) {
   if (file < 0)
     return UV_UNKNOWN_HANDLE;
 
+#if defined(__PASE__)
+  /* On IBMi PASE isatty() always returns true for stdin, stdout and stderr.
+   * Use ioctl() instead to identify whether it's actually a TTY.
+   */
+  if (!ioctl(file, TXISATTY + 0x81, NULL) || errno != ENOTTY)
+#else
   if (isatty(file))
+#endif
     return UV_TTY;
 
   if (fstat(file, &s))