diff --git a/firmware/config/stm32h7ems/efifeatures.h b/firmware/config/stm32h7ems/efifeatures.h
index 3b8d2e6633..6cce5e0e20 100644
--- a/firmware/config/stm32h7ems/efifeatures.h
+++ b/firmware/config/stm32h7ems/efifeatures.h
@@ -6,6 +6,7 @@
 #define EFI_MAP_AVERAGING FALSE
 
 #undef EFI_USE_FAST_ADC
+// https://github.com/rusefi/rusefi/issues/3301 "H7 is currently actually using fast ADC exclusively - it just needs a bit of plumbing to make it work."
 #define EFI_USE_FAST_ADC FALSE
 
 #undef EFI_MC33816