diff --git a/src/servo/servo.h b/src/servo/servo.h
index 1449682e..6199de2f 100644
--- a/src/servo/servo.h
+++ b/src/servo/servo.h
@@ -45,6 +45,7 @@ namespace upm {
  * the maximum period.
  *
  * @defgroup servo libupm-servo
+ * @ingroup seeed emax pwm servos
  */
 class Servo {
     public:
diff --git a/src/upm.h b/src/upm.h
index f1962649..4cf2ee9e 100644
--- a/src/upm.h
+++ b/src/upm.h
@@ -284,6 +284,12 @@
  * @ingroup byman
  */
 
+/**
+ * @brief EMax
+ * @defgroup emax EMax
+ * @ingroup byman
+ */
+
 /**
  * @brief EpicTinker
  * @defgroup epict EpicTinker