diff --git a/src/option.c b/src/option.c
index df2f8f5..0c6178d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -4908,7 +4908,7 @@
 		/* The color scheme must have set 'background' back to another
 		 * value, that's not what we want here.  Disable the color
 		 * scheme and set the colors again. */
-		do_unlet((char_u *)"g:colors_name");
+		do_unlet((char_u *)"g:colors_name", TRUE);
 		free_string_option(p_bg);
 		p_bg = vim_strsave((char_u *)(dark ? "dark" : "light"));
 		check_string_option(&p_bg);