diff --git a/src/05-first-logic.md b/src/05-first-logic.md
index 338f51d2b7c0f639fa0a879569f5bea5ef8847d5..280eeb7ede4e6a688c5f067fa3e5f61b59bfe829 100644
--- a/src/05-first-logic.md
+++ b/src/05-first-logic.md
@@ -38,5 +38,5 @@ Recursion is main method of repetition (loops are not very functional)
 ```haskell
 doubleAll :: [Int] -> [Int]
 doubleAll [] = []
-doubleAll (x:xs) = (x * 2) : xs
+doubleAll (x:xs) = (x * 2) : doubleAll xs
 ```