diff --git a/src/protobuf/qabstractprotobufserializer.h b/src/protobuf/qabstractprotobufserializer.h
index d8f8054a..b517cb7a 100644
--- a/src/protobuf/qabstractprotobufserializer.h
+++ b/src/protobuf/qabstractprotobufserializer.h
@@ -34,7 +34,7 @@ public:
 
     virtual ~QAbstractProtobufSerializer();
 
-    virtual QAbstractProtobufSerializer::DeserializationError deserializationError() const = 0;
+    virtual DeserializationError deserializationError() const = 0;
     virtual QString deserializationErrorString() const = 0;
 
     virtual void
diff --git a/src/protobuf/qprotobufjsonserializer.h b/src/protobuf/qprotobufjsonserializer.h
index ae973d81..3a2c236d 100644
--- a/src/protobuf/qprotobufjsonserializer.h
+++ b/src/protobuf/qprotobufjsonserializer.h
@@ -22,7 +22,7 @@ public:
     QProtobufJsonSerializer();
     ~QProtobufJsonSerializer() override;
 
-    QAbstractProtobufSerializer::DeserializationError deserializationError() const override;
+    DeserializationError deserializationError() const override;
     QString deserializationErrorString() const override;
 
 private:
diff --git a/src/protobuf/qprotobufserializer.h b/src/protobuf/qprotobufserializer.h
index 8dcb7145..9ff99190 100644
--- a/src/protobuf/qprotobufserializer.h
+++ b/src/protobuf/qprotobufserializer.h
@@ -23,7 +23,7 @@ public:
     QProtobufSerializer();
     ~QProtobufSerializer() override;
 
-    QProtobufSerializer::DeserializationError deserializationError() const override;
+    DeserializationError deserializationError() const override;
     QString deserializationErrorString() const override;
 
     void shouldPreserveUnknownFields(bool preserveUnknownFields);