diff --git a/serial.hpp b/serial.hpp
index 713c3331..e52a6a89 100644
--- a/serial.hpp
+++ b/serial.hpp
@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 #include <stdio.h>
+#include <string.h>
 #include <vector>
 #include <atomic>
 #include <sys/stat.h>