diff --git a/Sheet5/mylib.cpp b/Sheet5/mylib.cpp
index 8124fcb..9b0feb0 100644
--- a/Sheet5/mylib.cpp
+++ b/Sheet5/mylib.cpp
@@ -1,5 +1,5 @@
 #include "mylib.h"
-#include "algorithm"     // GH: transform()
+#include <algorithm>     // GH: transform()
 #include <cassert>       // assert()
 #include <cmath>
 #include <iostream>