diff --git a/src/assert.hh b/src/assert.hh
index ceee28f2..975ddca1 100644
--- a/src/assert.hh
+++ b/src/assert.hh
@@ -9,7 +9,7 @@ namespace Kakoune
 struct assert_failed : logic_error
 {
     assert_failed(const String& message);
-    String description() const;
+    String description() const override;
 
 private:
     String m_message;
diff --git a/src/exception.hh b/src/exception.hh
index 5aab02f6..0b68d39e 100644
--- a/src/exception.hh
+++ b/src/exception.hh
@@ -17,7 +17,7 @@ struct runtime_error : exception
     runtime_error(const String& description)
         : m_description(description) {}
 
-    String description() const { return m_description; }
+    String description() const override { return m_description; }
 
 private:
     String m_description;
diff --git a/src/register_manager.cc b/src/register_manager.cc
index e77510a1..11bae66a 100644
--- a/src/register_manager.cc
+++ b/src/register_manager.cc
@@ -11,13 +11,13 @@ namespace Kakoune
 class StaticRegister : public Register
 {
 public:
-    Register& operator=(const memoryview<String>& values)
+    Register& operator=(const memoryview<String>& values) override
     {
         m_content = std::vector<String>(values.begin(), values.end());
         return *this;
     }
 
-    memoryview<String> values(const Context&)
+    memoryview<String> values(const Context&) override
     {
         if (m_content.empty())
             return memoryview<String>(ms_empty);
@@ -40,12 +40,12 @@ public:
     DynamicRegister(RegisterRetriever function)
         : m_function(std::move(function)) {}
 
-    Register& operator=(const memoryview<String>& values)
+    Register& operator=(const memoryview<String>& values) override
     {
         throw runtime_error("this register is not assignable");
     }
 
-    memoryview<String> values(const Context& context)
+    memoryview<String> values(const Context& context) override
     {
         m_content = m_function(context);
         return StaticRegister::values(context);
diff --git a/src/selection.hh b/src/selection.hh
index 7081e427..18e1dbab 100644
--- a/src/selection.hh
+++ b/src/selection.hh
@@ -31,8 +31,10 @@ struct Selection : public BufferChangeListener
     void merge_with(const Selection& selection);
     void avoid_eol();
 
-    void on_insert(const BufferIterator& begin, const BufferIterator& end);
-    void on_erase(const BufferIterator& begin, const BufferIterator& end);
+    void on_insert(const BufferIterator& begin,
+                   const BufferIterator& end) override;
+    void on_erase(const BufferIterator& begin,
+                  const BufferIterator& end) override;
 
 private:
     BufferIterator m_first;
diff --git a/src/window.hh b/src/window.hh
index 119cf962..fd0598e4 100644
--- a/src/window.hh
+++ b/src/window.hh
@@ -49,8 +49,8 @@ private:
     Window(Buffer& buffer);
     Window(const Window&) = delete;
 
-    void on_incremental_insertion_end();
-    void on_option_changed(const String& name, const Option& option);
+    void on_incremental_insertion_end() override;
+    void on_option_changed(const String& name, const Option& option) override;
 
     void scroll_to_keep_cursor_visible_ifn();