diff --git a/.clang-tidy b/.clang-tidy
index 59b47c4ba..32bcfb0a5 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -5,12 +5,14 @@ Checks:
   cert-*,
   modernize-*,
   -modernize-avoid-c-arrays,
+  -modernize-use-nodiscard,
   -modernize-use-trailing-return-type,
   performance-*,
   -performance-avoid-endl
 '
 WarningsAsErrors:  '*'
-HeaderFilterRegex: ''
+HeaderFilterRegex: '.*'
+ExcludeHeaderFilterRegex: 'include/.*'
 UseColor: true
 FormatStyle: 'file'
 ExtraArgs: ['-std=c++17']
diff --git a/cpp/Ice/async/HelloI.h b/cpp/Ice/async/HelloI.h
index a0ff6a90d..57f5e5dd3 100644
--- a/cpp/Ice/async/HelloI.h
+++ b/cpp/Ice/async/HelloI.h
@@ -12,9 +12,9 @@ class HelloI : public Demo::Hello
 {
 public:
     HelloI(const std::shared_ptr<WorkQueue>&);
-    virtual void
-    sayHelloAsync(int, std::function<void()>, std::function<void(std::exception_ptr)>, const Ice::Current&);
-    virtual void shutdown(const Ice::Current&);
+    void
+    sayHelloAsync(int, std::function<void()>, std::function<void(std::exception_ptr)>, const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     std::shared_ptr<WorkQueue> _workQueue;
diff --git a/cpp/Ice/async/WorkQueue.cpp b/cpp/Ice/async/WorkQueue.cpp
index 3fc170c06..eb8ab87cf 100644
--- a/cpp/Ice/async/WorkQueue.cpp
+++ b/cpp/Ice/async/WorkQueue.cpp
@@ -8,8 +8,6 @@
 
 using namespace std;
 
-WorkQueue::WorkQueue() : _done(false) {}
-
 void
 WorkQueue::start()
 {
diff --git a/cpp/Ice/async/WorkQueue.h b/cpp/Ice/async/WorkQueue.h
index d9a0315f0..953ad788e 100644
--- a/cpp/Ice/async/WorkQueue.h
+++ b/cpp/Ice/async/WorkQueue.h
@@ -15,8 +15,6 @@
 class WorkQueue
 {
 public:
-    WorkQueue();
-
     void run();
 
     void add(int, std::function<void()>, std::function<void(std::exception_ptr)>);
@@ -31,7 +29,7 @@ class WorkQueue
     std::condition_variable _condition;
 
     std::list<CallbackEntry> _callbacks;
-    bool _done;
+    bool _done{false};
     std::thread _thread;
 };
 
diff --git a/cpp/Ice/asyncInvocation/CalculatorI.h b/cpp/Ice/asyncInvocation/CalculatorI.h
index 861a4fa3d..4cd0771c9 100644
--- a/cpp/Ice/asyncInvocation/CalculatorI.h
+++ b/cpp/Ice/asyncInvocation/CalculatorI.h
@@ -10,12 +10,12 @@
 class CalculatorI : public Demo::Calculator
 {
 public:
-    virtual int add(int, int, const Ice::Current&) override;
-    virtual int subtract(int, int, const Ice::Current&) override;
-    virtual int divide(int, int, int&, const Ice::Current&) override;
-    virtual int square(int, const Ice::Current&) override;
-    virtual double squareRoot(int, const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    int add(int, int, const Ice::Current&) override;
+    int subtract(int, int, const Ice::Current&) override;
+    int divide(int, int, int&, const Ice::Current&) override;
+    int square(int, const Ice::Current&) override;
+    double squareRoot(int, const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/Ice/context/ContextI.h b/cpp/Ice/context/ContextI.h
index 375d1addc..68cb0534d 100644
--- a/cpp/Ice/context/ContextI.h
+++ b/cpp/Ice/context/ContextI.h
@@ -10,8 +10,8 @@
 class ContextI : public Demo::Context
 {
 public:
-    virtual void call(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void call(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/Ice/hello/HelloI.h b/cpp/Ice/hello/HelloI.h
index 4d9fe917b..f82b52662 100644
--- a/cpp/Ice/hello/HelloI.h
+++ b/cpp/Ice/hello/HelloI.h
@@ -10,8 +10,8 @@
 class HelloI : public Demo::Hello
 {
 public:
-    virtual void sayHello(int delay, const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(int delay, const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/Ice/interceptor/AuthenticatorI.h b/cpp/Ice/interceptor/AuthenticatorI.h
index ee2b3676d..663c8d7f1 100644
--- a/cpp/Ice/interceptor/AuthenticatorI.h
+++ b/cpp/Ice/interceptor/AuthenticatorI.h
@@ -15,7 +15,7 @@ class AuthenticatorI : public Demo::Authenticator
 {
 public:
     AuthenticatorI();
-    virtual std::string getToken(const Ice::Current&) override;
+    std::string getToken(const Ice::Current&) override;
     void validateToken(const std::string&);
 
 private:
diff --git a/cpp/Ice/interceptor/ThermostatI.h b/cpp/Ice/interceptor/ThermostatI.h
index df9dde454..8aacf085b 100644
--- a/cpp/Ice/interceptor/ThermostatI.h
+++ b/cpp/Ice/interceptor/ThermostatI.h
@@ -11,9 +11,9 @@
 class ThermostatI : public Demo::Thermostat
 {
 public:
-    virtual float getTemp(const Ice::Current&) override;
-    virtual void setTemp(float, const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    float getTemp(const Ice::Current&) override;
+    void setTemp(float, const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     // Temperature in Celsius.
diff --git a/cpp/Ice/locator/HelloI.h b/cpp/Ice/locator/HelloI.h
index cc3c37a8b..0719926f3 100644
--- a/cpp/Ice/locator/HelloI.h
+++ b/cpp/Ice/locator/HelloI.h
@@ -10,8 +10,8 @@
 class HelloI : public Demo::Hello
 {
 public:
-    virtual void sayHello(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/Ice/minimal/HelloI.h b/cpp/Ice/minimal/HelloI.h
index 8800b5bf3..70284a59a 100644
--- a/cpp/Ice/minimal/HelloI.h
+++ b/cpp/Ice/minimal/HelloI.h
@@ -10,7 +10,7 @@
 class HelloI : public Demo::Hello
 {
 public:
-    virtual void sayHello(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/Ice/session/SessionI.cpp b/cpp/Ice/session/SessionI.cpp
index ef2d3fe14..7218ab477 100644
--- a/cpp/Ice/session/SessionI.cpp
+++ b/cpp/Ice/session/SessionI.cpp
@@ -26,7 +26,7 @@ class HelloI final : public Hello
     const int _id;
 };
 
-SessionI::SessionI(string name) : _name(std::move(name)), _nextId(0), _destroy(false)
+SessionI::SessionI(string name) : _name(std::move(name))
 {
     cout << "The session " << _name << " is now created." << endl;
 }
diff --git a/cpp/Ice/session/SessionI.h b/cpp/Ice/session/SessionI.h
index 8678a2675..cd0b55671 100644
--- a/cpp/Ice/session/SessionI.h
+++ b/cpp/Ice/session/SessionI.h
@@ -22,8 +22,8 @@ class SessionI final : public Demo::Session
 private:
     std::mutex _mutex;
     const std::string _name;
-    int _nextId; // The per-session id of the next hello object. This is used for tracing purposes.
+    int _nextId{0}; // The per-session id of the next hello object. This is used for tracing purposes.
     std::list<std::optional<Demo::HelloPrx>> _objs; // List of per-session allocated hello objects.
-    bool _destroy;
+    bool _destroy{false};
 };
 #endif
diff --git a/cpp/Ice/throughput/StringView.h b/cpp/Ice/throughput/StringView.h
index b2dde428d..cac260c72 100644
--- a/cpp/Ice/throughput/StringView.h
+++ b/cpp/Ice/throughput/StringView.h
@@ -93,7 +93,7 @@ namespace Ice
 
         template<class S> static inline void read(S* stream, Util::string_view& v)
         {
-            const char* vdata = 0;
+            const char* vdata = nullptr;
             size_t vsize = 0;
 
             stream->read(vdata, vsize);
diff --git a/cpp/Ice/throughput/ThroughputI.cpp b/cpp/Ice/throughput/ThroughputI.cpp
index 38316242e..61b91bf1e 100644
--- a/cpp/Ice/throughput/ThroughputI.cpp
+++ b/cpp/Ice/throughput/ThroughputI.cpp
@@ -9,8 +9,7 @@ ThroughputI::ThroughputI()
     : _byteSeq(Demo::ByteSeqSize),
       _stringSeq(Demo::StringSeqSize, "hello"),
       _structSeq(Demo::StringDoubleSeqSize, {"hello", 3.14}),
-      _fixedSeq(Demo::FixedSeqSize, {0, 0, 0.0}),
-      _warmup(false)
+      _fixedSeq(Demo::FixedSeqSize, {0, 0, 0.0})
 {
 }
 
diff --git a/cpp/Ice/throughput/ThroughputI.h b/cpp/Ice/throughput/ThroughputI.h
index 4cf5b64f3..4d028733f 100644
--- a/cpp/Ice/throughput/ThroughputI.h
+++ b/cpp/Ice/throughput/ThroughputI.h
@@ -40,7 +40,7 @@ class ThroughputI final : public Demo::Throughput
     Demo::StringDoubleSeq _structSeq;
     Demo::FixedSeq _fixedSeq;
 
-    bool _warmup;
+    bool _warmup{false};
 };
 
 #endif
diff --git a/cpp/IceBox/hello/HelloI.h b/cpp/IceBox/hello/HelloI.h
index 8800b5bf3..70284a59a 100644
--- a/cpp/IceBox/hello/HelloI.h
+++ b/cpp/IceBox/hello/HelloI.h
@@ -10,7 +10,7 @@
 class HelloI : public Demo::Hello
 {
 public:
-    virtual void sayHello(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/IceBox/hello/HelloServiceI.h b/cpp/IceBox/hello/HelloServiceI.h
index 19e1e1e17..3754948cd 100644
--- a/cpp/IceBox/hello/HelloServiceI.h
+++ b/cpp/IceBox/hello/HelloServiceI.h
@@ -10,9 +10,9 @@
 class HelloServiceI : public IceBox::Service
 {
 public:
-    virtual void start(const std::string&, const std::shared_ptr<Ice::Communicator>&, const Ice::StringSeq&) override;
+    void start(const std::string&, const std::shared_ptr<Ice::Communicator>&, const Ice::StringSeq&) override;
 
-    virtual void stop() override;
+    void stop() override;
 
 private:
     std::shared_ptr<Ice::ObjectAdapter> _adapter;
diff --git a/cpp/IceDiscovery/hello/HelloI.h b/cpp/IceDiscovery/hello/HelloI.h
index 4d9fe917b..f82b52662 100644
--- a/cpp/IceDiscovery/hello/HelloI.h
+++ b/cpp/IceDiscovery/hello/HelloI.h
@@ -10,8 +10,8 @@
 class HelloI : public Demo::Hello
 {
 public:
-    virtual void sayHello(int delay, const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(int delay, const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 };
 
 #endif
diff --git a/cpp/IceDiscovery/replication/HelloI.h b/cpp/IceDiscovery/replication/HelloI.h
index 1491573e4..347b47dbc 100644
--- a/cpp/IceDiscovery/replication/HelloI.h
+++ b/cpp/IceDiscovery/replication/HelloI.h
@@ -12,8 +12,8 @@ class HelloI : public Demo::Hello
 public:
     HelloI(std::string);
 
-    virtual std::string getGreeting(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    std::string getGreeting(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     const std::string _name;
diff --git a/cpp/IceGrid/allocate/HelloI.h b/cpp/IceGrid/allocate/HelloI.h
index 125e4aac7..18cbd22a0 100644
--- a/cpp/IceGrid/allocate/HelloI.h
+++ b/cpp/IceGrid/allocate/HelloI.h
@@ -12,8 +12,8 @@ class HelloI : public Demo::Hello
 public:
     HelloI(std::string);
 
-    virtual void sayHello(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     const std::string _name;
diff --git a/cpp/IceGrid/customLocator/HelloI.h b/cpp/IceGrid/customLocator/HelloI.h
index 125e4aac7..18cbd22a0 100644
--- a/cpp/IceGrid/customLocator/HelloI.h
+++ b/cpp/IceGrid/customLocator/HelloI.h
@@ -12,8 +12,8 @@ class HelloI : public Demo::Hello
 public:
     HelloI(std::string);
 
-    virtual void sayHello(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     const std::string _name;
diff --git a/cpp/IceGrid/icebox/HelloI.h b/cpp/IceGrid/icebox/HelloI.h
index 3e054cce9..473687e10 100644
--- a/cpp/IceGrid/icebox/HelloI.h
+++ b/cpp/IceGrid/icebox/HelloI.h
@@ -12,7 +12,7 @@ class HelloI : public Demo::Hello
 public:
     HelloI(std::string);
 
-    virtual void sayHello(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
 
 private:
     const std::string _serviceName;
diff --git a/cpp/IceGrid/icebox/HelloServiceI.h b/cpp/IceGrid/icebox/HelloServiceI.h
index 19e1e1e17..3754948cd 100644
--- a/cpp/IceGrid/icebox/HelloServiceI.h
+++ b/cpp/IceGrid/icebox/HelloServiceI.h
@@ -10,9 +10,9 @@
 class HelloServiceI : public IceBox::Service
 {
 public:
-    virtual void start(const std::string&, const std::shared_ptr<Ice::Communicator>&, const Ice::StringSeq&) override;
+    void start(const std::string&, const std::shared_ptr<Ice::Communicator>&, const Ice::StringSeq&) override;
 
-    virtual void stop() override;
+    void stop() override;
 
 private:
     std::shared_ptr<Ice::ObjectAdapter> _adapter;
diff --git a/cpp/IceGrid/secure/HelloI.h b/cpp/IceGrid/secure/HelloI.h
index 125e4aac7..18cbd22a0 100644
--- a/cpp/IceGrid/secure/HelloI.h
+++ b/cpp/IceGrid/secure/HelloI.h
@@ -12,8 +12,8 @@ class HelloI : public Demo::Hello
 public:
     HelloI(std::string);
 
-    virtual void sayHello(const Ice::Current&) override;
-    virtual void shutdown(const Ice::Current&) override;
+    void sayHello(const Ice::Current&) override;
+    void shutdown(const Ice::Current&) override;
 
 private:
     const std::string _name;
diff --git a/cpp/IceStorm/counter/CounterObserverI.h b/cpp/IceStorm/counter/CounterObserverI.h
index e4cafb9d1..9ac099a72 100644
--- a/cpp/IceStorm/counter/CounterObserverI.h
+++ b/cpp/IceStorm/counter/CounterObserverI.h
@@ -13,8 +13,8 @@ void print(const std::string&);
 class CounterObserverI : public Demo::CounterObserver
 {
 public:
-    virtual void init(int, const Ice::Current&) override;
-    virtual void inc(int, const Ice::Current&) override;
+    void init(int, const Ice::Current&) override;
+    void inc(int, const Ice::Current&) override;
 
 private:
     int _value = 0;
diff --git a/cpp/Manual/simpleFilesystem/FilesystemI.h b/cpp/Manual/simpleFilesystem/FilesystemI.h
index c75365e88..54919df75 100644
--- a/cpp/Manual/simpleFilesystem/FilesystemI.h
+++ b/cpp/Manual/simpleFilesystem/FilesystemI.h
@@ -2,8 +2,8 @@
 // Copyright (c) ZeroC, Inc. All rights reserved.
 //
 
-#ifndef __FilesystemI_h__
-#define __FilesystemI_h__
+#ifndef FilesystemI_h
+#define FilesystemI_h
 
 #include <Filesystem.h>
 #include <Ice/Ice.h>
@@ -21,7 +21,7 @@ namespace Filesystem
     class NodeI : public virtual Node, public std::enable_shared_from_this<NodeI>
     {
     public:
-        virtual std::string name(const Ice::Current&) override;
+        std::string name(const Ice::Current&) override;
         NodeI(std::string, const std::shared_ptr<DirectoryI>&);
         void activate(const std::shared_ptr<Ice::ObjectAdapter>&);