diff --git a/ocaml-lessons/lesson4/step6/step.html b/ocaml-lessons/lesson4/step6/step.html
index fa65ded..837571a 100644
--- a/ocaml-lessons/lesson4/step6/step.html
+++ b/ocaml-lessons/lesson4/step6/step.html
@@ -10,7 +10,7 @@ <h3>Exhaustiveness</h3>
   | h::_ -> h
 </code></pre>
 
-Moreover, the compiler will also warm the user when a case is handled
+Moreover, the compiler will also warn the user when a case is handled
 multiple times or when a case is unused:
 
 <pre><code>let head = function