diff --git a/firmware/controllers/algo/engine.h b/firmware/controllers/algo/engine.h
index 70d83de0cd..dcc9e7dfd0 100644
--- a/firmware/controllers/algo/engine.h
+++ b/firmware/controllers/algo/engine.h
@@ -298,11 +298,6 @@ typedef struct {
 	uint32_t rpmCbTime;
 } monitoring_timestamps_s;
 
-class Engine;
-class WallFuel;
-
-typedef void (*configuration_callback_t)(Engine*);
-
 class FsioState {
 public:
 	FsioState();
@@ -592,4 +587,6 @@ void prepareOutputSignals(DECLARE_ENGINE_PARAMETER_SIGNATURE);
 void validateConfiguration(DECLARE_ENGINE_PARAMETER_SIGNATURE);
 void doScheduleStopEngine(DECLARE_ENGINE_PARAMETER_SIGNATURE);
 
+typedef void (*configuration_callback_t)(Engine*);
+
 #endif /* H_ENGINE_H_ */