diff --git a/haskell.html.markdown b/haskell.html.markdown
index 2437ceed..f3baa9a5 100644
--- a/haskell.html.markdown
+++ b/haskell.html.markdown
@@ -120,6 +120,10 @@ snd ("haskell", 1) -- 1
 -- A simple function that takes two variables
 add a b = a + b
 
+-- Note that if you are using ghci (the Haskell interpreter)
+-- You'll need to use `let`, i.e.
+-- let add a b = a + b
+
 -- Using the function
 add 1 2 -- 3