diff --git a/src/fsfw/health/HasHealthIF.h b/src/fsfw/health/HasHealthIF.h
index 41abeef33..197f08aad 100644
--- a/src/fsfw/health/HasHealthIF.h
+++ b/src/fsfw/health/HasHealthIF.h
@@ -16,10 +16,15 @@ class HasHealthIF {
   };
 
   static const uint8_t INTERFACE_ID = CLASS_ID::HAS_HEALTH_IF;
-  static const ReturnValue_t OBJECT_NOT_HEALTHY = MAKE_RETURN_CODE(1);
-  static const ReturnValue_t INVALID_HEALTH_STATE = MAKE_RETURN_CODE(2);
+  static constexpr ReturnValue_t OBJECT_NOT_HEALTHY =
+      HasReturnvaluesIF::makeReturnCode(INTERFACE_ID, 1);
+  static constexpr ReturnValue_t INVALID_HEALTH_STATE =
+      HasReturnvaluesIF::makeReturnCode(INTERFACE_ID, 2);
+  static constexpr ReturnValue_t IS_EXTERNALLY_CONTROLLED =
+      HasReturnvaluesIF::makeReturnCode(INTERFACE_ID, 3);
 
   static const uint8_t SUBSYSTEM_ID = SUBSYSTEM_ID::SYSTEM_MANAGER_1;
+  //! P1: New Health, P2: Old Health
   static const Event HEALTH_INFO = MAKE_EVENT(6, severity::INFO);
   static const Event CHILD_CHANGED_HEALTH = MAKE_EVENT(7, severity::INFO);
   static const Event CHILD_PROBLEMS = MAKE_EVENT(8, severity::LOW);