diff --git a/README.md b/README.md
index 923a98b..fad8b15 100644
--- a/README.md
+++ b/README.md
@@ -78,7 +78,7 @@ You can bind the `*enabled*` special variable to `nil` to control the colorizati
     (cons (real 0 256)
           (cons (real 0 256)
                 (cons (real 0 256)
-                      nil)))
+                      null)))
     cl-colors:rgb
     cl-colors:hsv
     term-colors
diff --git a/src/cl-ansi-text.lisp b/src/cl-ansi-text.lisp
index a758209..7e99122 100644
--- a/src/cl-ansi-text.lisp
+++ b/src/cl-ansi-text.lisp
@@ -105,7 +105,7 @@ the terminal setting -- For example, many terminals do not use `FF0000` for the
        (cons (real 0 256)
              (cons (real 0 256)
                    (cons (real 0 256)
-                         nil)))
+                         null)))
        cl-colors2:rgb
        cl-colors2:hsv
        term-colors