diff --git a/src/utf8.h b/src/utf8.h
index a2b2c9d..8d03a74 100644
--- a/src/utf8.h
+++ b/src/utf8.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstring>
 #include <cstdint>
 #include <vector>
 #include <string>