diff --git a/Kernel/Devices/HID/KeyboardDevice.h b/Kernel/Devices/HID/KeyboardDevice.h
index 35585d6836..28a9a77d35 100644
--- a/Kernel/Devices/HID/KeyboardDevice.h
+++ b/Kernel/Devices/HID/KeyboardDevice.h
@@ -30,7 +30,7 @@ public:
     virtual bool can_write(const FileDescription&, size_t) const override { return true; }
 
     // ^HIDDevice
-    virtual Type instrument_type() const { return Type::Keyboard; }
+    virtual Type instrument_type() const override { return Type::Keyboard; }
 
     // ^Device
     virtual mode_t required_mode() const override { return 0440; }
diff --git a/Kernel/Devices/HID/MouseDevice.h b/Kernel/Devices/HID/MouseDevice.h
index a0e3c35f75..bc0d112301 100644
--- a/Kernel/Devices/HID/MouseDevice.h
+++ b/Kernel/Devices/HID/MouseDevice.h
@@ -29,7 +29,7 @@ public:
     virtual bool can_write(const FileDescription&, size_t) const override { return true; }
 
     // ^HIDDevice
-    virtual Type instrument_type() const { return Type::Mouse; }
+    virtual Type instrument_type() const override { return Type::Mouse; }
 
     // ^Device
     virtual mode_t required_mode() const override { return 0440; }
diff --git a/Kernel/Devices/MemoryDevice.h b/Kernel/Devices/MemoryDevice.h
index 688d81275b..21163ec727 100644
--- a/Kernel/Devices/MemoryDevice.h
+++ b/Kernel/Devices/MemoryDevice.h
@@ -30,7 +30,7 @@ private:
     virtual const char* class_name() const override { return "MemoryDevice"; }
     virtual bool can_read(const FileDescription&, size_t) const override { return true; }
     virtual bool can_write(const FileDescription&, size_t) const override { return false; }
-    virtual bool is_seekable() const { return true; }
+    virtual bool is_seekable() const override { return true; }
     virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
     virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override { return -EINVAL; }
 
diff --git a/Kernel/FileSystem/FIFO.h b/Kernel/FileSystem/FIFO.h
index d0cefd91db..52b6343e9d 100644
--- a/Kernel/FileSystem/FIFO.h
+++ b/Kernel/FileSystem/FIFO.h
@@ -32,8 +32,11 @@ public:
     KResultOr<NonnullRefPtr<FileDescription>> open_direction(Direction);
     KResultOr<NonnullRefPtr<FileDescription>> open_direction_blocking(Direction);
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverloaded-virtual"
     void attach(Direction);
     void detach(Direction);
+#pragma GCC diagnostic pop
 
 private:
     // ^File
diff --git a/Kernel/Interrupts/IOAPIC.h b/Kernel/Interrupts/IOAPIC.h
index c52709676e..6607c9db22 100644
--- a/Kernel/Interrupts/IOAPIC.h
+++ b/Kernel/Interrupts/IOAPIC.h
@@ -50,7 +50,7 @@ public:
     virtual u16 get_isr() const override;
     virtual u16 get_irr() const override;
     virtual u32 gsi_base() const override { return m_gsi_base; }
-    virtual size_t interrupt_vectors_count() const { return m_redirection_entries_count; }
+    virtual size_t interrupt_vectors_count() const override { return m_redirection_entries_count; }
     virtual const char* model() const override { return "IOAPIC"; };
     virtual IRQControllerType type() const override { return IRQControllerType::i82093AA; }
 
diff --git a/Kernel/Interrupts/IRQHandler.h b/Kernel/Interrupts/IRQHandler.h
index 08e2e9bd32..ffd8ec9f52 100644
--- a/Kernel/Interrupts/IRQHandler.h
+++ b/Kernel/Interrupts/IRQHandler.h
@@ -18,7 +18,7 @@ class IRQHandler : public GenericInterruptHandler {
 public:
     virtual ~IRQHandler();
 
-    virtual bool handle_interrupt(const RegisterState& regs) { return handle_irq(regs); }
+    virtual bool handle_interrupt(const RegisterState& regs) override { return handle_irq(regs); }
     virtual bool handle_irq(const RegisterState&) = 0;
 
     void enable_irq();
diff --git a/Kernel/Interrupts/PIC.h b/Kernel/Interrupts/PIC.h
index acd29143fe..b68ba899a0 100644
--- a/Kernel/Interrupts/PIC.h
+++ b/Kernel/Interrupts/PIC.h
@@ -23,7 +23,7 @@ public:
     virtual u16 get_isr() const override;
     virtual u16 get_irr() const override;
     virtual u32 gsi_base() const override { return 0; }
-    virtual size_t interrupt_vectors_count() const { return 16; }
+    virtual size_t interrupt_vectors_count() const override { return 16; }
     virtual const char* model() const override { return "Dual i8259"; }
     virtual IRQControllerType type() const override { return IRQControllerType::i8259; }
 
diff --git a/Kernel/Storage/BMIDEChannel.h b/Kernel/Storage/BMIDEChannel.h
index 2a8309dbdf..7810212d73 100644
--- a/Kernel/Storage/BMIDEChannel.h
+++ b/Kernel/Storage/BMIDEChannel.h
@@ -42,9 +42,9 @@ private:
     virtual bool handle_irq(const RegisterState&) override;
 
     //* IDEChannel
-    virtual void send_ata_io_command(LBAMode lba_mode, Direction direction) const;
-    virtual void ata_read_sectors(bool, u16);
-    virtual void ata_write_sectors(bool, u16);
+    virtual void send_ata_io_command(LBAMode lba_mode, Direction direction) const override;
+    virtual void ata_read_sectors(bool, u16) override;
+    virtual void ata_write_sectors(bool, u16) override;
 
     PhysicalRegionDescriptor& prdt() { return *reinterpret_cast<PhysicalRegionDescriptor*>(m_prdt_region->vaddr().as_ptr()); }
     OwnPtr<Region> m_prdt_region;
diff --git a/Kernel/Time/APICTimer.h b/Kernel/Time/APICTimer.h
index 6a48050486..0b6c5f5cc0 100644
--- a/Kernel/Time/APICTimer.h
+++ b/Kernel/Time/APICTimer.h
@@ -31,7 +31,7 @@ public:
     virtual bool is_capable_of_frequency(size_t frequency) const override;
     virtual size_t calculate_nearest_possible_frequency(size_t frequency) const override;
 
-    void will_be_destroyed() { HardwareTimer<GenericInterruptHandler>::will_be_destroyed(); }
+    void will_be_destroyed() override { HardwareTimer<GenericInterruptHandler>::will_be_destroyed(); }
     void enable_local_timer();
     void disable_local_timer();
 
diff --git a/Kernel/Time/HardwareTimer.h b/Kernel/Time/HardwareTimer.h
index ce555075e3..76adb108f6 100644
--- a/Kernel/Time/HardwareTimer.h
+++ b/Kernel/Time/HardwareTimer.h
@@ -132,7 +132,7 @@ public:
 
     virtual size_t sharing_devices_count() const override { return 0; }
     virtual bool is_shared_handler() const override { return false; }
-    virtual bool is_sharing_with_others() const { return false; }
+    virtual bool is_sharing_with_others() const override { return false; }
     virtual HandlerType type() const override { return HandlerType::IRQHandler; }
     virtual const char* controller() const override { return nullptr; }
     virtual bool eoi() override;