diff --git a/firmware/CHANGELOG.md b/firmware/CHANGELOG.md
index 42709ff74b..281399f99f 100644
--- a/firmware/CHANGELOG.md
+++ b/firmware/CHANGELOG.md
@@ -28,6 +28,7 @@ Release template (copy/paste this for new release):
 ### Added
 
 ### Fixed
+ - Lua canRxAdd bus parameter handling #4467
 
 ### Removed
 
diff --git a/firmware/controllers/lua/can_filter.cpp b/firmware/controllers/lua/can_filter.cpp
index e4880ae9a8..a332258f7e 100644
--- a/firmware/controllers/lua/can_filter.cpp
+++ b/firmware/controllers/lua/can_filter.cpp
@@ -27,10 +27,6 @@ void resetLuaCanRx() {
 }
 
 void addLuaCanRxFilter(int32_t eid, uint32_t mask, int bus, int callback) {
-    if (bus != ANY_BUS && !isValidHwCanBusIndex(bus)) {
-		efiPrintf("LUA CAN bus index %d is not valid", bus);
-    }
-
 	if (filterCount >= maxFilterCount) {
 		firmwareError(OBD_PCM_Processor_Fault, "Too many Lua CAN RX filters");
 	}
diff --git a/firmware/controllers/lua/lua_hooks.cpp b/firmware/controllers/lua/lua_hooks.cpp
index d11d5946ab..159919ec33 100644
--- a/firmware/controllers/lua/lua_hooks.cpp
+++ b/firmware/controllers/lua/lua_hooks.cpp
@@ -136,10 +136,16 @@ static uint32_t getArray(lua_State* l, int paramIndex, uint8_t *data, uint32_t s
 }
 
 #if EFI_CAN_SUPPORT || EFI_UNIT_TEST
-static int lua_txCan(lua_State* l) {
-	auto channel = luaL_checkinteger(l, 1);
+
+static int validateCanChannelAndConvertFromHumanIntoZeroIndex(lua_State* l) {
+	lua_Integer channel = luaL_checkinteger(l, 1);
 	// TODO: support multiple channels
-	luaL_argcheck(l, channel == 1 || channel == 2, 1, "only channels 1 and 2 currently supported");
+	luaL_argcheck(l, channel == 1 || channel == 2, 1, "only buses 1 and 2 currently supported");
+	return channel - HUMAN_OFFSET;
+}
+
+static int lua_txCan(lua_State* l) {
+	auto bus = validateCanChannelAndConvertFromHumanIntoZeroIndex(l);
 
 	auto id = luaL_checkinteger(l, 2);
 	auto ext = luaL_checkinteger(l, 3);
@@ -153,7 +159,7 @@ static int lua_txCan(lua_State* l) {
 
 	// conform ext parameter to true/false
 	CanTxMessage msg(CanCategory::LUA, id, 8, ext == 0 ? false : true);
-	msg.busIndex = channel - HUMAN_OFFSET;
+	msg.busIndex = bus;
 
 	// Unfortunately there is no way to inspect the length of a table,
 	// so we have to just iterate until we run out of numbers
@@ -212,6 +218,7 @@ struct P {
 static P luaL_checkPwmIndex(lua_State* l, int pos) {
 	auto channel = luaL_checkinteger(l, pos);
 
+    // todo: what a mess :( CAN buses start at 1 and PWM channels start at 0 :(
 	// Ensure channel is valid
 	if (channel < 0 || channel >= LUA_PWM_COUNT) {
 		luaL_error(l, "setPwmDuty invalid channel %d", channel);
@@ -483,14 +490,14 @@ int lua_canRxAdd(lua_State* l) {
 				callback = getLuaFunc(l);
 			} else {
 				// handle canRxAdd(bus, id)
-				bus = luaL_checkinteger(l, 1);
+				bus = validateCanChannelAndConvertFromHumanIntoZeroIndex(l);
 				eid = luaL_checkinteger(l, 2);
 			}
 
 			break;
 		case 3:
 			// handle canRxAdd(bus, id, callback)
-			bus = luaL_checkinteger(l, 1);
+			bus = validateCanChannelAndConvertFromHumanIntoZeroIndex(l);
 			eid = luaL_checkinteger(l, 2);
 			lua_remove(l, 1);
 			lua_remove(l, 1);
@@ -530,7 +537,7 @@ int lua_canRxAddMask(lua_State* l) {
 				callback = getLuaFunc(l);
 			} else {
 				// handle canRxAddMask(bus, id, mask)
-				bus = luaL_checkinteger(l, 1);
+		    	bus = validateCanChannelAndConvertFromHumanIntoZeroIndex(l);
 				eid = luaL_checkinteger(l, 2);
 				mask = luaL_checkinteger(l, 3);
 			}
@@ -538,7 +545,7 @@ int lua_canRxAddMask(lua_State* l) {
 			break;
 		case 4:
 			// handle canRxAddMask(bus, id, mask, callback)
-			bus = luaL_checkinteger(l, 1);
+			bus = validateCanChannelAndConvertFromHumanIntoZeroIndex(l);
 			eid = luaL_checkinteger(l, 2);
 			mask = luaL_checkinteger(l, 3);
 			lua_remove(l, 1);
diff --git a/firmware/hw_layer/drivers/can/can_hw.cpp b/firmware/hw_layer/drivers/can/can_hw.cpp
index 4b46399c9a..b3630d6d53 100644
--- a/firmware/hw_layer/drivers/can/can_hw.cpp
+++ b/firmware/hw_layer/drivers/can/can_hw.cpp
@@ -334,8 +334,3 @@ bool getIsCanEnabled(void) {
 }
 
 #endif /* EFI_CAN_SUPPORT */
-
-bool isValidHwCanBusIndex(const size_t busIndex) {
-    // 'size_t' is an unsigned type so we are never below zero here
-	return (busIndex <= 1);
-}
diff --git a/firmware/hw_layer/drivers/can/can_hw.h b/firmware/hw_layer/drivers/can/can_hw.h
index 14f8792959..fe471a4313 100644
--- a/firmware/hw_layer/drivers/can/can_hw.h
+++ b/firmware/hw_layer/drivers/can/can_hw.h
@@ -25,5 +25,3 @@ void postCanState();
 #endif /* EFI_TUNER_STUDIO */
 
 #endif /* EFI_CAN_SUPPORT */
-
-bool isValidHwCanBusIndex(const size_t busIndex);