diff --git a/internal/messaging/processor.go b/internal/messaging/processor.go
index 2704b9c4..5360a1e9 100644
--- a/internal/messaging/processor.go
+++ b/internal/messaging/processor.go
@@ -292,7 +292,6 @@ func (p *messageProcessor) ProcessIncomingLocalMessageAndGetResponse(
 	}
 	p.logger.Infof("responseMsg before processing %v", responseMsg.Content)
 	if err := p.responseHandler.ProcessRequestMessage(ctx, responseMsg, requestMsg.Content); err != nil {
-		// TODO: @VjeraTurk or AddErrorToResponseHeader earlier?!
 		p.responseHandler.AddErrorToResponseHeader(responseMsg.Content, err.Error())
 		return ctx, responseMsg, fmt.Errorf("failed to process request message: %w", err)
 	}
diff --git a/internal/messaging/response_handler.go b/internal/messaging/response_handler.go
index ab3e9b16..caa80b72 100644
--- a/internal/messaging/response_handler.go
+++ b/internal/messaging/response_handler.go
@@ -6,6 +6,7 @@ package messaging
 import (
 	"context"
 	"crypto/ecdsa"
+	"fmt"
 	"log"
 	"time"
 
@@ -127,7 +128,7 @@ func (h *evmResponseHandler) ProcessRequestMessage(
 	/*
 		Cancellation messages will serve as an example of this type
 	*/
-	return nil
+	return fmt.Errorf("method ProcessRequestMessage: not implemented")
 }
 
 // Prepares response by performing any necessary modifications to it.