diff --git a/src/if_ruby.c b/src/if_ruby.c
index d609d34..a7a7772 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -1449,7 +1449,7 @@
 
 static VALUE window_set_width(VALUE self UNUSED, VALUE width)
 {
-#ifdef FEAT_VERTSPLIT
+#ifdef FEAT_WINDOWS
     win_T *win = get_win(self);
     win_T *savewin = curwin;