diff --git a/src/libvterm/bin/unterm.c b/src/libvterm/bin/unterm.c
index acaf2d2..b8fe37c 100644
--- a/src/libvterm/bin/unterm.c
+++ b/src/libvterm/bin/unterm.c
@@ -265,7 +265,7 @@
   }
 
   vt = vterm_new(rows, cols);
-  vterm_set_utf8(vt, true);
+  vterm_set_utf8(vt, TRUE);
 
   vts = vterm_obtain_screen(vt);
   vterm_screen_set_callbacks(vts, &cb_screen, NULL);