diff --git a/debuggers/common/dialogs/selectcoredialog.h b/debuggers/common/dialogs/selectcoredialog.h
--- a/debuggers/common/dialogs/selectcoredialog.h
+++ b/debuggers/common/dialogs/selectcoredialog.h
@@ -32,7 +32,7 @@
 class SelectCoreDialog : public QDialog
 {
 public:
-    SelectCoreDialog(QWidget *parent = 0);
+    SelectCoreDialog(QWidget *parent = nullptr);
     QUrl binary() const;
     QUrl core() const;
 
diff --git a/debuggers/common/mi/mi.h b/debuggers/common/mi/mi.h
--- a/debuggers/common/mi/mi.h
+++ b/debuggers/common/mi/mi.h
@@ -241,8 +241,8 @@
     */
     struct Result
     {
-        Result() : value(0) {}
-        ~Result() { delete value; value = 0; }
+        Result() : value(nullptr) {}
+        ~Result() { delete value; value = nullptr; }
 
         QString variable;
         Value *value;
diff --git a/debuggers/common/mi/micommand.h b/debuggers/common/mi/micommand.h
--- a/debuggers/common/mi/micommand.h
+++ b/debuggers/common/mi/micommand.h
@@ -82,7 +82,7 @@
 public:
     typedef std::function<void (const ResultRecord&)> Function;
 
-    FunctionCommandHandler(const Function& callback, CommandFlags flags = 0);
+    FunctionCommandHandler(const Function& callback, CommandFlags flags = nullptr);
 
     virtual void handle(const ResultRecord&) override;
     virtual bool handlesError() override;
@@ -99,7 +99,7 @@
 class MICommand
 {
 protected:
-    MICommand(CommandType type, const QString& arguments = QString(), CommandFlags flags = 0);
+    MICommand(CommandType type, const QString& arguments = QString(), CommandFlags flags = nullptr);
     friend class KDevMI::MIDebugSession;
 
 public:
@@ -254,7 +254,7 @@
     CliCommand(CommandType type, const QString& command,
                Handler* handler_this,
                void (Handler::* handler_method)(const QStringList&),
-               CommandFlags flags = 0);
+               CommandFlags flags = nullptr);
 };
 
 /** Command that does nothing and can be just used to invoke
@@ -269,7 +269,7 @@
     template<class Handler>
     SentinelCommand(Handler* handler_this,
                     void (Handler::* handler_method)(),
-                    CommandFlags flags = 0)
+                    CommandFlags flags = nullptr)
         : MICommand(NonMI, QString(), flags)
     {
         QPointer<Handler> guarded_this(handler_this);
@@ -280,7 +280,7 @@
         };
     }
 
-    SentinelCommand(const Function& handler, CommandFlags flags = 0)
+    SentinelCommand(const Function& handler, CommandFlags flags = nullptr)
         : MICommand(NonMI, QString(), flags)
         , handler(handler)
     {
diff --git a/debuggers/common/mi/milexer.h b/debuggers/common/mi/milexer.h
--- a/debuggers/common/mi/milexer.h
+++ b/debuggers/common/mi/milexer.h
@@ -44,7 +44,7 @@
     TokenStream *tokenStream;
 
     inline FileSymbol()
-        : tokenStream(0) {}
+        : tokenStream(nullptr) {}
 
     inline ~FileSymbol();
 };
@@ -142,7 +142,7 @@
 inline FileSymbol::~FileSymbol()
 {
     delete tokenStream;
-    tokenStream = 0;
+    tokenStream = nullptr;
 }
 
 } // end of MI
diff --git a/debuggers/common/mibreakpointcontroller.h b/debuggers/common/mibreakpointcontroller.h
--- a/debuggers/common/mibreakpointcontroller.h
+++ b/debuggers/common/mibreakpointcontroller.h
@@ -101,7 +101,7 @@
 
     void createFromDebugger(const MI::Value& miBkpt);
     void updateFromDebugger(int row, const MI::Value& miBkpt,
-                       KDevelop::BreakpointModel::ColumnFlags lockedColumns = 0);
+                       KDevelop::BreakpointModel::ColumnFlags lockedColumns = nullptr);
 
     int rowFromDebuggerId(int gdbId) const;
 
diff --git a/debuggers/common/registers/registercontroller_arm.h b/debuggers/common/registers/registercontroller_arm.h
--- a/debuggers/common/registers/registercontroller_arm.h
+++ b/debuggers/common/registers/registercontroller_arm.h
@@ -31,7 +31,7 @@
 {
 public:
 
-    RegisterController_Arm(MIDebugSession* debugSession = 0, QObject* parent = 0);
+    RegisterController_Arm(MIDebugSession* debugSession = nullptr, QObject* parent = nullptr);
 
     virtual QVector<GroupsName> namesOfRegisterGroups() const override;
 
diff --git a/debuggers/common/registers/registercontroller_x86.h b/debuggers/common/registers/registercontroller_x86.h
--- a/debuggers/common/registers/registercontroller_x86.h
+++ b/debuggers/common/registers/registercontroller_x86.h
@@ -36,7 +36,7 @@
     virtual void updateRegisters(const GroupsName& group = GroupsName()) override;
 
 protected:
-    RegisterControllerGeneral_x86(MIDebugSession* debugSession = 0, QObject* parent = 0);
+    RegisterControllerGeneral_x86(MIDebugSession* debugSession = nullptr, QObject* parent = nullptr);
 
     virtual RegistersGroup registersFromGroup(const GroupsName& group) const override;
 
@@ -71,7 +71,7 @@
 {
 
 public:
-    RegisterController_x86(MIDebugSession* debugSession = 0, QObject* parent = 0);
+    RegisterController_x86(MIDebugSession* debugSession = nullptr, QObject* parent = nullptr);
 
 private:
     void initRegisterNames();
@@ -81,7 +81,7 @@
 {
 
 public:
-    RegisterController_x86_64(MIDebugSession* debugSession = 0, QObject* parent = 0);
+    RegisterController_x86_64(MIDebugSession* debugSession = nullptr, QObject* parent = nullptr);
 
 private:
     void initRegisterNames();
diff --git a/debuggers/gdb/memviewdlg.h b/debuggers/gdb/memviewdlg.h
--- a/debuggers/gdb/memviewdlg.h
+++ b/debuggers/gdb/memviewdlg.h
@@ -42,7 +42,7 @@
     {
         Q_OBJECT
     public:
-        MemoryViewerWidget(CppDebuggerPlugin* plugin, QWidget* parent = 0);
+        MemoryViewerWidget(CppDebuggerPlugin* plugin, QWidget* parent = nullptr);
 
     public Q_SLOTS:
         /** Adds a new memory view. */
diff --git a/debuggers/lldb/lldbcommand.h b/debuggers/lldb/lldbcommand.h
--- a/debuggers/lldb/lldbcommand.h
+++ b/debuggers/lldb/lldbcommand.h
@@ -36,7 +36,7 @@
 {
 protected:
     LldbCommand(MI::CommandType type, const QString& arguments = QString(),
-                MI::CommandFlags flags = 0);
+                MI::CommandFlags flags = nullptr);
     friend class KDevMI::LLDB::DebugSession;
 public:
     ~LldbCommand();
diff --git a/documentation/qthelp/qthelpnetwork.h b/documentation/qthelp/qthelpnetwork.h
--- a/documentation/qthelp/qthelpnetwork.h
+++ b/documentation/qthelp/qthelpnetwork.h
@@ -74,7 +74,7 @@
 
 	protected:
 		virtual QNetworkReply *createRequest(Operation op,
-			const QNetworkRequest &request, QIODevice *outgoingData = 0) override;
+			const QNetworkRequest &request, QIODevice *outgoingData = nullptr) override;
 
 	private:
 		QHelpEngineCore *m_helpEngine;
diff --git a/languages/clang/duchain/clangparsingenvironmentfile.h b/languages/clang/duchain/clangparsingenvironmentfile.h
--- a/languages/clang/duchain/clangparsingenvironmentfile.h
+++ b/languages/clang/duchain/clangparsingenvironmentfile.h
@@ -39,7 +39,7 @@
     ClangParsingEnvironmentFile(ClangParsingEnvironmentFileData& data);
     ~ClangParsingEnvironmentFile();
 
-    virtual bool needsUpdate(const KDevelop::ParsingEnvironment* environment = 0) const override;
+    virtual bool needsUpdate(const KDevelop::ParsingEnvironment* environment = nullptr) const override;
     virtual int type() const override;
 
     virtual bool matchEnvironment(const KDevelop::ParsingEnvironment* environment) const override;
diff --git a/languages/clang/duchain/cursorkindtraits.h b/languages/clang/duchain/cursorkindtraits.h
--- a/languages/clang/duchain/cursorkindtraits.h
+++ b/languages/clang/duchain/cursorkindtraits.h
@@ -261,7 +261,7 @@
          : TK == CXType_ObjCId  ? "id"
          : TK == CXType_ObjCSel ? "SEL"
          : TK == CXType_NullPtr ? "nullptr_t"
-         : 0;
+         : nullptr;
 }
 
 }
diff --git a/projectmanagers/cmake/cmakedoc.h b/projectmanagers/cmake/cmakedoc.h
--- a/projectmanagers/cmake/cmakedoc.h
+++ b/projectmanagers/cmake/cmakedoc.h
@@ -33,7 +33,7 @@
         virtual QString name() const override { return mName; }
         virtual KDevelop::IDocumentationProvider* provider() const override;
         
-        virtual QWidget* documentationWidget(KDevelop::DocumentationFindWidget* findWidget, QWidget* parent = 0) override;
+        virtual QWidget* documentationWidget(KDevelop::DocumentationFindWidget* findWidget, QWidget* parent = nullptr) override;
         
         static CMakeDocumentation* s_provider;
         
diff --git a/projectmanagers/cmake/duchain/contextbuilder.h b/projectmanagers/cmake/duchain/contextbuilder.h
--- a/projectmanagers/cmake/duchain/contextbuilder.h
+++ b/projectmanagers/cmake/duchain/contextbuilder.h
@@ -33,7 +33,7 @@
     virtual KDevelop::RangeInRevision editorFindRange(CMakeContentIterator* fromNode, CMakeContentIterator* toNode) override;
     virtual KDevelop::QualifiedIdentifier identifierForNode(CMakeFunctionDesc* node) override;
     virtual void setContextOnNode(CMakeContentIterator* node, KDevelop::DUContext* context) override;
-    virtual KDevelop::TopDUContext* newTopContext(const KDevelop::RangeInRevision& range, KDevelop::ParsingEnvironmentFile* file = 0) override;
+    virtual KDevelop::TopDUContext* newTopContext(const KDevelop::RangeInRevision& range, KDevelop::ParsingEnvironmentFile* file = nullptr) override;
 };
 
 #endif // CONTEXTBUILDER_H
diff --git a/projectmanagers/custom-buildsystem/custombuildsystemplugin.h b/projectmanagers/custom-buildsystem/custombuildsystemplugin.h
--- a/projectmanagers/custom-buildsystem/custombuildsystemplugin.h
+++ b/projectmanagers/custom-buildsystem/custombuildsystemplugin.h
@@ -42,7 +42,7 @@
     Q_INTERFACES( KDevelop::IProjectFileManager )
     Q_INTERFACES( KDevelop::IBuildSystemManager )
 public:
-    explicit CustomBuildSystem( QObject *parent = 0, const QVariantList &args = QVariantList() );
+    explicit CustomBuildSystem( QObject *parent = nullptr, const QVariantList &args = QVariantList() );
     virtual ~CustomBuildSystem();
 
 // ProjectBuilder API
@@ -65,7 +65,7 @@
 public:
     Features features() const override;
     virtual KDevelop::ProjectFolderItem* createFolderItem( KDevelop::IProject* project, 
-                    const KDevelop::Path& path, KDevelop::ProjectBaseItem* parent = 0 ) override;
+                    const KDevelop::Path& path, KDevelop::ProjectBaseItem* parent = nullptr ) override;
 
 // BuildSystemManager API
 public:
diff --git a/projectmanagers/qmake/parser/tests/testhelpers.h b/projectmanagers/qmake/parser/tests/testhelpers.h
--- a/projectmanagers/qmake/parser/tests/testhelpers.h
+++ b/projectmanagers/qmake/parser/tests/testhelpers.h
@@ -67,7 +67,7 @@
 #define ENDTESTFUNCIMPL }
 
 #define TESTASSIGNMENT( ast, var, opval, valcount ) \
-    QVERIFY( ast != 0 );\
+    QVERIFY( ast != nullptr );\
     QVERIFY( ast->identifier->value == var );\
     QVERIFY( ast->op->value == opval );\
     QVERIFY( ast->values.count() == valcount );
@@ -100,7 +100,7 @@
     }
 
 #define TESTSCOPEBODY( scope, teststmts, stmtcount ) \
-    QVERIFY( scope->body != 0 ); \
+    QVERIFY( scope->body != nullptr ); \
     QVERIFY( scope->body->statements.count() == stmtcount ); \
     matchScopeBodies(scope->body->statements, teststmts);