diff --git a/applications/message_handler/message_handler.hpp b/applications/message_handler/message_handler.hpp
index 90b1cd2..13a3c60 100644
--- a/applications/message_handler/message_handler.hpp
+++ b/applications/message_handler/message_handler.hpp
@@ -24,7 +24,9 @@
 #include "semphr.h"
 
 #include "message_queue.hpp"
+#if defined(ETHOSU)
 #include <ethosu_driver.h>
+#endif
 #include <inference_process.hpp>
 #include <mailbox.hpp>
 
@@ -65,8 +67,10 @@
 
     bool getInferenceJob(const EthosU::ethosu_core_inference_req &req, InferenceProcess::InferenceJob &job);
 
+#if defined(ETHOSU)
     friend void ::ethosu_inference_begin(struct ethosu_driver *drv, void *userArg);
     friend void ::ethosu_inference_end(struct ethosu_driver *drv, void *userArg);
+#endif
 
     QueueHandle_t inferenceQueue;
     QueueHandle_t outputQueue;