diff --git a/firmware/controllers/core/interpolation.cpp b/firmware/controllers/core/interpolation.cpp
index 04a2a021fd..2df7475deb 100644
--- a/firmware/controllers/core/interpolation.cpp
+++ b/firmware/controllers/core/interpolation.cpp
@@ -173,6 +173,7 @@ int findIndex2(const float array[], unsigned size, float value) {
 void ensureArrayIsAscending(const char *msg, const float array[], int size) {
 	for (int i = 0; i < size - 1; i ++) {
 		if (array[i] >= array[i+ 1]) {
+			// todo: this should become a warning under https://github.com/rusefi/rusefi/issues/440
 			firmwareError(CUSTOM_ERR_AXIS_ORDER, "invalid axis %s at %f", msg, array[i]);
 		}
 	}