diff --git a/firmware/controllers/algo/rusefi_types.h b/firmware/controllers/algo/rusefi_types.h
index 84895e57e0..72cebd5533 100644
--- a/firmware/controllers/algo/rusefi_types.h
+++ b/firmware/controllers/algo/rusefi_types.h
@@ -27,6 +27,7 @@
 #define FOUR_STROKE_CYCLE_DURATION 720
 
 // gasoline E0
+// todo: some usages should be migrated to getStoichiometricRatio()
 #define STOICH_RATIO 14.7f
 #define CONST_PI 3.14159265358979323846
 
diff --git a/firmware/controllers/sensors/sensor_type.h b/firmware/controllers/sensors/sensor_type.h
index e4ac717dde..69298b8788 100644
--- a/firmware/controllers/sensors/sensor_type.h
+++ b/firmware/controllers/sensors/sensor_type.h
@@ -63,6 +63,7 @@ enum class SensorType : unsigned char {
 	AuxTemp1, // 20
 	AuxTemp2,
 
+  // this becomes AFR once we multiply by STOICH_RATIO
 	Lambda1,
 	Lambda2,
 
diff --git a/firmware/init/sensor/init_lambda.cpp b/firmware/init/sensor/init_lambda.cpp
index f978747c26..15d732fcd3 100644
--- a/firmware/init/sensor/init_lambda.cpp
+++ b/firmware/init/sensor/init_lambda.cpp
@@ -7,10 +7,10 @@
 
 struct GetAfrWrapper {
 	float getLambda() {
-		return getAfr(SensorType::Lambda1) / 14.7f;
+		return getAfr(SensorType::Lambda1) / STOICH_RATIO;
 	};
 	float getLambda2() {
-		return getAfr(SensorType::Lambda2) / 14.7f;
+		return getAfr(SensorType::Lambda2) / STOICH_RATIO;
 	}
 };