diff --git a/u01/node.cpp b/u01/node.cpp
index ece43ab..b1ff337 100644
--- a/u01/node.cpp
+++ b/u01/node.cpp
@@ -77,7 +77,7 @@ std::string node::print_iterative() const {
       if (n != this)
         output << std::endl;
       output << std::string(depth, '\t') << n->get_name();
-      // Complex iteration (not default vector iteration is necessary,
+      // Complex iteration (not default vector iteration) is necessary,
       // to achieve the same output as the recursive approach.
       // Otherwise, the order of the children is reversed (due to LIFO).
       for (std::size_t i = n->get_nr_children(); i > 0; i--) {