diff --git a/src/externalextractor.h b/src/externalextractor.h
index d003ea2..fdccac3 100644
--- a/src/externalextractor.h
+++ b/src/externalextractor.h
@@ -1,50 +1,50 @@
 /*
  * This file is part of the KFileMetaData project
  * Copyright (C) 2016  Varun Joshi <varunj.1011@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) version 3, or any
  * later version accepted by the membership of KDE e.V. (or its
  * successor approved by the membership of KDE e.V.), which shall
  * act as a proxy defined in Section 6 of version 3 of the license.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
 
 #ifndef EXTERNALEXTRACTOR_H
 #define EXTERNALEXTRACTOR_H
 
 #include "extractorplugin.h"
 
 namespace KFileMetaData {
 
 class ExternalExtractor : public ExtractorPlugin
 {
 
     Q_OBJECT
 
 public:
     explicit ExternalExtractor(QObject* parent = nullptr);
-    ExternalExtractor(const QString& pluginPath);
+    explicit ExternalExtractor(const QString& pluginPath);
     virtual ~ExternalExtractor();
 
     QStringList mimetypes() const override;
     void extract(ExtractionResult* result) override;
 
 private:
     class ExternalExtractorPrivate;
     ExternalExtractorPrivate *d_ptr;
     Q_DECLARE_PRIVATE(ExternalExtractor)
 };
 }
 
 #endif // EXTERNALEXTRACTOR_H
diff --git a/src/writers/taglibwriter.h b/src/writers/taglibwriter.h
index 0f72b1a..65e8639 100644
--- a/src/writers/taglibwriter.h
+++ b/src/writers/taglibwriter.h
@@ -1,45 +1,45 @@
 /*
  * Copyright (C) 2016 Varun Joshi <varunj.1011@gmail.com>
  * Copyright (C) 2018 Alexander Stippich <a.stippich@gmx.net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */
 
 #ifndef TAGLIBWRITER_H
 #define TAGLIBWRITER_H
 
 #include "writerplugin.h"
 
 namespace KFileMetaData
 {
 
 class TagLibWriter : public WriterPlugin
 {
     Q_OBJECT
     Q_PLUGIN_METADATA(IID "org.kde.kf5.kfilemetadata.WriterPlugin")
     Q_INTERFACES(KFileMetaData::WriterPlugin)
 
 public:
-    TagLibWriter(QObject* parent = nullptr);
+    explicit TagLibWriter(QObject* parent = nullptr);
 
     void write(const WriteData& data) override;
     QStringList writeMimetypes() const override;
 };
 
 }
 
 #endif // TAGLIBWRITER_H