diff --git a/src/midi/MidiGraph.hpp b/src/midi/MidiGraph.hpp
index 6fb3865..011b8b7 100644
--- a/src/midi/MidiGraph.hpp
+++ b/src/midi/MidiGraph.hpp
@@ -5,6 +5,7 @@
 #include <memory>
 #include <set>
 #include <span>
+#include <string>
 #include <string_view>
 #include <vector>