diff --git a/internal/processor/midi-message-encode.go b/internal/processor/midi-message-encode.go
index 968e5b3..8cf344d 100644
--- a/internal/processor/midi-message-encode.go
+++ b/internal/processor/midi-message-encode.go
@@ -18,7 +18,7 @@ func (mme *MIDIMessageEncode) Process(ctx context.Context, payload any) (any, er
 	payloadMessage, ok := payload.(midi.Message)
 
 	if !ok {
-		return nil, errors.New("midi.message.encode processor only accepts an midi.Message")
+		return nil, errors.New("midi.message.encode processor only accepts a midi.Message")
 	}
 
 	return payloadMessage.Bytes(), nil
diff --git a/internal/processor/midi-message-filter.go b/internal/processor/midi-message-filter.go
index 75954a6..fef2c37 100644
--- a/internal/processor/midi-message-filter.go
+++ b/internal/processor/midi-message-filter.go
@@ -19,7 +19,7 @@ func (mmf *MIDIMessageFilter) Process(ctx context.Context, payload any) (any, er
 	payloadMessage, ok := payload.(midi.Message)
 
 	if !ok {
-		return nil, errors.New("midi.message.filter processor only accepts an midi.Message")
+		return nil, errors.New("midi.message.filter processor only accepts a midi.Message")
 	}
 
 	if payloadMessage.Type().String() != mmf.MIDIType {
diff --git a/internal/processor/nats-message-encode.go b/internal/processor/nats-message-encode.go
index efaa6c3..8494866 100644
--- a/internal/processor/nats-message-encode.go
+++ b/internal/processor/nats-message-encode.go
@@ -16,7 +16,7 @@ func (nme *NATSMessageEncode) Process(ctx context.Context, payload any) (any, er
 	payloadMessage, ok := payload.(*nats.Msg)
 
 	if !ok {
-		return nil, errors.New("nats.message.encode processor only accepts an nats.Msg")
+		return nil, errors.New("nats.message.encode processor only accepts a nats.Msg")
 	}
 
 	return payloadMessage.Data, nil