diff --git a/src/main/scala/org/lemon/advent/lib/collections.scala b/src/main/scala/org/lemon/advent/lib/collections.scala
index 3091462..4fccbbb 100644
--- a/src/main/scala/org/lemon/advent/lib/collections.scala
+++ b/src/main/scala/org/lemon/advent/lib/collections.scala
@@ -18,7 +18,7 @@ extension [A](it: Iterator[A])
 
 extension [A](it: Iterable[A])
   /** Returns an iterator view of the Cartesian product of this iterable and another.
-    * Also known as the cross product
+    * Also known as the cross product.
     *
     * @param rhs the other iterable
     * @return all pairs of elements (a, b) where a is from this iterable and b is from the other iterable