diff --git a/firmware/controllers/algo/engine_types.h b/firmware/controllers/algo/engine_types.h
index 3548ff170e..685827ffbb 100644
--- a/firmware/controllers/algo/engine_types.h
+++ b/firmware/controllers/algo/engine_types.h
@@ -242,7 +242,7 @@ typedef enum {
 	TEST_108 = 108,
 	TEST_109 = 109,
 	TEST_110 = 110,
-
+   // todo: Technical debt: ENUM_32_BITS #3874
 	Force_4_bytes_size_engine_type = ENUM_32_BITS,
 } engine_type_e;
 
diff --git a/firmware/integration/rusefi_config.txt b/firmware/integration/rusefi_config.txt
index 86bd0d1da6..e7ed85ad89 100644
--- a/firmware/integration/rusefi_config.txt
+++ b/firmware/integration/rusefi_config.txt
@@ -88,6 +88,7 @@ struct_no_prefix engine_configuration_s
 
 ! Back in the day we wanted enums to be 32 bit integers.
 ! as of 2020 preference is with ' __attribute__ ((__packed__))' allowing one-byte enums
+! todo: Technical debt: ENUM_32_BITS #3874
 #define ENUM_16_BITS 60000
 #define ENUM_32_BITS 2000000000