diff --git a/YACReaderLibrary/db/comic_model.h b/YACReaderLibrary/db/comic_model.h
index 5d7f95bc..4d9c0594 100644
--- a/YACReaderLibrary/db/comic_model.h
+++ b/YACReaderLibrary/db/comic_model.h
@@ -64,8 +64,8 @@ public:
     };
 
 public:
-    ComicModel(QObject *parent = 0);
-    ComicModel(QSqlQuery &sqlquery, QObject *parent = 0);
+    explicit ComicModel(QObject *parent = nullptr);
+    explicit ComicModel(QSqlQuery &sqlquery, QObject *parent = nullptr);
     ~ComicModel() override;
 
     QVariant data(const QModelIndex &index, int role) const override;
@@ -75,13 +75,13 @@ public:
     QModelIndex index(int row, int column,
                       const QModelIndex &parent = QModelIndex()) const override;
     QModelIndex parent(const QModelIndex &index) const override;
-    int rowCount(const QModelIndex &parent = QModelIndex()) const;
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     int columnCount(const QModelIndex &parent = QModelIndex()) const override;
     bool canDropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const override;
     bool dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override;
     bool canBeResorted();
-    QMimeData *mimeData(const QModelIndexList &indexes) const;
-    QStringList mimeTypes() const;
+    QMimeData *mimeData(const QModelIndexList &indexes) const override;
+    QStringList mimeTypes() const override;
 
     void setupFolderModelData(unsigned long long int parentFolder, const QString &databasePath);
     void setupLabelModelData(unsigned long long int parentLabel, const QString &databasePath);
diff --git a/YACReaderLibrary/db/folder_model.h b/YACReaderLibrary/db/folder_model.h
index cb49cdda..8eb19af1 100644
--- a/YACReaderLibrary/db/folder_model.h
+++ b/YACReaderLibrary/db/folder_model.h
@@ -17,7 +17,7 @@ class FolderModelProxy : public QSortFilterProxyModel
 {
     Q_OBJECT
 public:
-    explicit FolderModelProxy(QObject *parent = 0);
+    explicit FolderModelProxy(QObject *parent = nullptr);
     ~FolderModelProxy() override;
 
     void setFilterData(QMap<unsigned long long, FolderItem *> *filteredItems, FolderItem *root);
@@ -42,8 +42,8 @@ class FolderModel : public QAbstractItemModel
     friend class YACReader::FolderQueryResultProcessor;
 
 public:
-    FolderModel(QObject *parent = 0);
-    FolderModel(QSqlQuery &sqlquery, QObject *parent = 0);
+    explicit FolderModel(QObject *parent = nullptr);
+    explicit FolderModel(QSqlQuery &sqlquery, QObject *parent = nullptr);
     ~FolderModel() override;
 
     //QAbstractItemModel methods
diff --git a/YACReaderLibrary/db/reading_list_model.h b/YACReaderLibrary/db/reading_list_model.h
index 5a22a02a..71d66b92 100644
--- a/YACReaderLibrary/db/reading_list_model.h
+++ b/YACReaderLibrary/db/reading_list_model.h
@@ -19,14 +19,14 @@ class ReadingListModelProxy : public QSortFilterProxyModel
 {
     Q_OBJECT
 public:
-    explicit ReadingListModelProxy(QObject *parent = 0);
+    explicit ReadingListModelProxy(QObject *parent = nullptr);
 };
 
 class ReadingListModel : public QAbstractItemModel
 {
     Q_OBJECT
 public:
-    explicit ReadingListModel(QObject *parent = 0);
+    explicit ReadingListModel(QObject *parent = nullptr);
 
     //QAbstractItemModel methods
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;