diff --git a/Firmware/mmu2.cpp b/Firmware/mmu2.cpp
index cedacdc4fc..e365927327 100644
--- a/Firmware/mmu2.cpp
+++ b/Firmware/mmu2.cpp
@@ -197,7 +197,7 @@ void MMU2::mmu_loop() {
     if (is_mmu_error_monitor_active){
         // Call this every iteration to keep the knob rotation responsive
         // This includes when mmu_loop is called within manage_response
-        ReportErrorHook((uint16_t)lastErrorCode);
+        ReportErrorHook((uint16_t)lastErrorCode, mmu2.MMUCurrentErrorCode() == ErrorCode::OK ? ErrorSourcePrinter : ErrorSourceMMU);
     }
 
     avoidRecursion = false;
@@ -728,19 +728,19 @@ StepStatus MMU2::LogicStep() {
         OnMMUProgressMsg(logic.Progress());
         break;
     case CommandError:
-        ReportError(logic.Error());
+        ReportError(logic.Error(), ErrorSourceMMU);
         break;
     case CommunicationTimeout:
         state = xState::Connecting;
-        ReportError(ErrorCode::MMU_NOT_RESPONDING);
+        ReportError(ErrorCode::MMU_NOT_RESPONDING, ErrorSourcePrinter);
         break;
     case ProtocolError:
         state = xState::Connecting;
-        ReportError(ErrorCode::PROTOCOL_ERROR);
+        ReportError(ErrorCode::PROTOCOL_ERROR, ErrorSourcePrinter);
         break;
     case VersionMismatch:
         StopKeepPowered();
-        ReportError(ErrorCode::VERSION_MISMATCH);
+        ReportError(ErrorCode::VERSION_MISMATCH, ErrorSourcePrinter);
         break;
     case ButtonPushed:
         lastButton = logic.Button();
@@ -778,7 +778,7 @@ void MMU2::SetActiveExtruder(uint8_t ex){
     active_extruder = ex; 
 }
 
-void MMU2::ReportError(ErrorCode ec) {
+void MMU2::ReportError(ErrorCode ec, uint8_t res) {
     // Due to a potential lossy error reporting layers linked to this hook
     // we'd better report everything to make sure especially the error states
     // do not get lost. 
@@ -805,7 +805,7 @@ void MMU2::ReportError(ErrorCode ec) {
         break;
     }
 
-    ReportErrorHook((uint16_t)ec);
+    ReportErrorHook((uint16_t)ec, res);
 
     if( ec != lastErrorCode ){ // deduplicate: only report changes in error codes into the log
         lastErrorCode = ec;
diff --git a/Firmware/mmu2.h b/Firmware/mmu2.h
index a3c614eefa..a1cd8ee7a5 100644
--- a/Firmware/mmu2.h
+++ b/Firmware/mmu2.h
@@ -68,7 +68,13 @@ class MMU2 {
         Cooldown = 2, // The extruder was allowed to cool.
         CooldownPending = 4,
     };
-    
+
+    /// Source of operation error
+    enum ReportErrorSource: uint8_t {
+        ErrorSourcePrinter = 0,
+        ErrorSourceMMU = 1,
+    };
+
     /// Perform a reset of the MMU
     /// @param level physical form of the reset
     void Reset(ResetForm level);
@@ -199,7 +205,8 @@ class MMU2 {
 
     /// Reports an error into attached ExtUIs
     /// @param ec error code, see ErrorCode
-    void ReportError(ErrorCode ec);
+    /// @param res reporter error source, is either Printer (0) or MMU (1)
+    void ReportError(ErrorCode ec, uint8_t res);
 
     /// Reports progress of operations into attached ExtUIs
     /// @param pc progress code, see ProgressCode
diff --git a/Firmware/mmu2_reporting.cpp b/Firmware/mmu2_reporting.cpp
index f16a295c3e..9c0d583a47 100644
--- a/Firmware/mmu2_reporting.cpp
+++ b/Firmware/mmu2_reporting.cpp
@@ -198,17 +198,11 @@ enum class ReportErrorHookStates : uint8_t {
 
 enum ReportErrorHookStates ReportErrorHookState = ReportErrorHookStates::RENDER_ERROR_SCREEN;
 
-/**
- * @brief Render MMU error screen on the LCD. This must be non-blocking
- * and allow the MMU and printer to communicate with each other.
- * @param[in] ec Error code
- */
-void ReportErrorHook(uint16_t ec) {
-
-//    SERIAL_ECHOPGM("ReportErrorHookState=");
-//    SERIAL_ECHOLN((int)ReportErrorHookState);
-
-    if (mmu2.MMUCurrentErrorCode() == ErrorCode::OK) {
+/// @brief Render MMU error screen on the LCD. This must be non-blocking
+/// and allow the MMU and printer to communicate with each other.
+/// @param[in] ec Error code
+void ReportErrorHook(uint16_t ec, uint8_t res) {
+    if (mmu2.MMUCurrentErrorCode() == ErrorCode::OK && res == MMU2::ErrorSourceMMU) {
         // If the error code suddenly changes to OK, that means
         // a button was pushed on the MMU and the LCD should
         // dismiss the error screen until MMU raises a new error
diff --git a/Firmware/mmu2_reporting.h b/Firmware/mmu2_reporting.h
index 8cb5317805..7e9fa587fb 100644
--- a/Firmware/mmu2_reporting.h
+++ b/Firmware/mmu2_reporting.h
@@ -22,8 +22,14 @@ void BeginReport(CommandInProgress cip, uint16_t ec);
 /// Called at the end of every MMU operation
 void EndReport(CommandInProgress cip, uint16_t ec);
 
-/// Called when the MMU sends operation error (even repeatedly)
-void ReportErrorHook(uint16_t ec);
+/**
+ * @brief Called when the MMU or MK3S sends operation error (even repeatedly).
+ * Render MMU error screen on the LCD. This must be non-blocking
+ * and allow the MMU and printer to communicate with each other.
+ * @param[in] ec error code
+ * @param[in] res reporter error source, is either Printer (0) or MMU (1)
+ */
+void ReportErrorHook(uint16_t ec, uint8_t res);
 
 /// Called when the MMU sends operation progress update
 void ReportProgressHook(CommandInProgress cip, uint16_t ec);