diff --git a/docs/drivers.rst b/docs/drivers.rst
index f091bd6e..1e360119 100644
--- a/docs/drivers.rst
+++ b/docs/drivers.rst
@@ -297,6 +297,7 @@ this time developed in C:
 
     #include <stdio.h>
     #include <stdlib.h>
+    #include <string.h>
     #include <moordyn/MoorDyn2.h>
 
     int main(int, char**)