diff --git a/doc/example-packet-drv.c b/doc/example-packet-drv.c
index 0c617ccc2..9ac01a6cd 100644
--- a/doc/example-packet-drv.c
+++ b/doc/example-packet-drv.c
@@ -33,6 +33,11 @@ u8_t
 example_packet_driver_output(void)
 {
   let_the_hardware_send_the_packet(uip_buf, uip_len);
+
+  /*
+   * An network device driver returns always zero.
+   */
+  return 0;
 }
 /*---------------------------------------------------------------------------*/
 /*
diff --git a/doc/example-packet-drv.h b/doc/example-packet-drv.h
new file mode 100644
index 000000000..64a7c3cff
--- /dev/null
+++ b/doc/example-packet-drv.h
@@ -0,0 +1,24 @@
+/*
+ * This is an example of how to write a network device driver ("packet
+ * driver") for Contiki.
+ */
+
+#ifndef __EXAMPLE_PACKET_DRV_H__
+#define __EXAMPLE_PACKET_DRV_H__
+
+/*
+ * We include the "contiki.h" file to get the macro and typedef used below.
+ */
+#include "contiki.h"
+
+/*
+ * Here we declare the process name used to start it (typically from main()).
+ */
+PROCESS_NAME(example_packet_driver_process);
+
+/*
+ * Finally we declare the output function for use with uIP packet forwarding.
+ */
+u8_t example_packet_driver_output(void);
+
+#endif /* __EXAMPLE_PACKET_DRV_H__ */