diff --git a/src/browser/NativeMessagingHost.h b/src/browser/NativeMessagingHost.h
index da9ac534..774306d3 100644
--- a/src/browser/NativeMessagingHost.h
+++ b/src/browser/NativeMessagingHost.h
@@ -41,8 +41,8 @@ signals:
     void quit();
 
 private:
-    void readLength();
-    bool readStdIn(const quint32 length);
+    void readLength() override;
+    bool readStdIn(const quint32 length) override;
     void sendReplyToAllClients(const QJsonObject& json);
 
 private slots:
diff --git a/src/cli/Add.h b/src/cli/Add.h
index 5769249c..dd0c3d8b 100644
--- a/src/cli/Add.h
+++ b/src/cli/Add.h
@@ -25,7 +25,7 @@ class Add : public Command
 public:
     Add();
     ~Add();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_ADD_H
diff --git a/src/cli/Clip.h b/src/cli/Clip.h
index 929ddf67..e5e6390a 100644
--- a/src/cli/Clip.h
+++ b/src/cli/Clip.h
@@ -25,7 +25,7 @@ class Clip : public Command
 public:
     Clip();
     ~Clip();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
     int clipEntry(Database* database, const QString& entryPath, const QString& timeout);
 };
 
diff --git a/src/cli/Diceware.h b/src/cli/Diceware.h
index 61fe724c..f439681b 100644
--- a/src/cli/Diceware.h
+++ b/src/cli/Diceware.h
@@ -25,7 +25,7 @@ class Diceware : public Command
 public:
     Diceware();
     ~Diceware();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_DICEWARE_H
diff --git a/src/cli/Edit.h b/src/cli/Edit.h
index 2c413bea..001b5aba 100644
--- a/src/cli/Edit.h
+++ b/src/cli/Edit.h
@@ -25,7 +25,7 @@ class Edit : public Command
 public:
     Edit();
     ~Edit();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_EDIT_H
diff --git a/src/cli/Estimate.h b/src/cli/Estimate.h
index 15f92275..c15fed9b 100644
--- a/src/cli/Estimate.h
+++ b/src/cli/Estimate.h
@@ -25,7 +25,7 @@ class Estimate : public Command
 public:
     Estimate();
     ~Estimate();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_ESTIMATE_H
diff --git a/src/cli/Extract.h b/src/cli/Extract.h
index 2939afdd..1a4f6288 100644
--- a/src/cli/Extract.h
+++ b/src/cli/Extract.h
@@ -25,7 +25,7 @@ class Extract : public Command
 public:
     Extract();
     ~Extract();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_EXTRACT_H
diff --git a/src/cli/Generate.h b/src/cli/Generate.h
index 607fc105..64ef8162 100644
--- a/src/cli/Generate.h
+++ b/src/cli/Generate.h
@@ -25,7 +25,7 @@ class Generate : public Command
 public:
     Generate();
     ~Generate();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_GENERATE_H
diff --git a/src/cli/List.h b/src/cli/List.h
index 5697d939..92ade262 100644
--- a/src/cli/List.h
+++ b/src/cli/List.h
@@ -25,7 +25,7 @@ class List : public Command
 public:
     List();
     ~List();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
     int listGroup(Database* database, bool recursive, const QString& groupPath = {});
 };
 
diff --git a/src/cli/Locate.h b/src/cli/Locate.h
index 3355d41e..ae32951b 100644
--- a/src/cli/Locate.h
+++ b/src/cli/Locate.h
@@ -25,7 +25,7 @@ class Locate : public Command
 public:
     Locate();
     ~Locate();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
     int locateEntry(Database* database, const QString& searchTerm);
 };
 
diff --git a/src/cli/Merge.h b/src/cli/Merge.h
index 496c66b8..1f138b65 100644
--- a/src/cli/Merge.h
+++ b/src/cli/Merge.h
@@ -25,7 +25,7 @@ class Merge : public Command
 public:
     Merge();
     ~Merge();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
 };
 
 #endif // KEEPASSXC_MERGE_H
diff --git a/src/cli/Remove.h b/src/cli/Remove.h
index 33d62f4b..d45e04af 100644
--- a/src/cli/Remove.h
+++ b/src/cli/Remove.h
@@ -27,7 +27,7 @@ class Remove : public Command
 public:
     Remove();
     ~Remove();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
     int removeEntry(Database* database, const QString& databasePath, const QString& entryPath);
 };
 
diff --git a/src/cli/Show.h b/src/cli/Show.h
index fe16546c..6d49d120 100644
--- a/src/cli/Show.h
+++ b/src/cli/Show.h
@@ -25,7 +25,7 @@ class Show : public Command
 public:
     Show();
     ~Show();
-    int execute(const QStringList& arguments);
+    int execute(const QStringList& arguments) override;
     int showEntry(Database* database, QStringList attributes, const QString& entryPath);
 };
 
diff --git a/src/format/KeePass1Reader.cpp b/src/format/KeePass1Reader.cpp
index 7c0ea652..a991b572 100644
--- a/src/format/KeePass1Reader.cpp
+++ b/src/format/KeePass1Reader.cpp
@@ -37,7 +37,7 @@
 class KeePass1Key : public CompositeKey
 {
 public:
-    virtual QByteArray rawKey() const;
+    QByteArray rawKey() const override;
     virtual void clear();
     void setPassword(const QByteArray& password);
     void setKeyfileData(const QByteArray& keyfileData);