diff --git a/serial.cpp b/serial.cpp
index a9a96d99..03f72d72 100644
--- a/serial.cpp
+++ b/serial.cpp
@@ -7,6 +7,7 @@
 #include <sqlite3.h>
 #include <set>
 #include <map>
+#include <algorithm>
 #include <limits.h>
 #include "protozero/varint.hpp"
 #include "geometry.hpp"