diff --git a/src/lib/context.cpp b/src/lib/context.cpp
--- a/src/lib/context.cpp
+++ b/src/lib/context.cpp
@@ -28,17 +28,6 @@
 
 using namespace KSyntaxHighlighting;
 
-Context::Context()
-    : m_resolveState(Unknown)
-    , m_fallthrough(false)
-    , m_noIndentationBasedFolding(false)
-{
-}
-
-Context::~Context()
-{
-}
-
 Definition Context::definition() const
 {
     return m_def.definition();
diff --git a/src/lib/context_p.h b/src/lib/context_p.h
--- a/src/lib/context_p.h
+++ b/src/lib/context_p.h
@@ -33,8 +33,8 @@
 class Context
 {
 public:
-    Context();
-    ~Context();
+    Context() = default;
+    ~Context() = default;
 
     Definition definition() const;
     void setDefinition(const DefinitionRef &def);
@@ -85,9 +85,9 @@
 
     QVector<Rule::Ptr> m_rules;
 
-    ResolveState m_resolveState;
-    bool m_fallthrough;
-    bool m_noIndentationBasedFolding;
+    ResolveState m_resolveState = Unknown;
+    bool m_fallthrough = false;
+    bool m_noIndentationBasedFolding = false;
 };
 }
 
diff --git a/src/lib/contextswitch.cpp b/src/lib/contextswitch.cpp
--- a/src/lib/contextswitch.cpp
+++ b/src/lib/contextswitch.cpp
@@ -24,16 +24,6 @@
 
 using namespace KSyntaxHighlighting;
 
-ContextSwitch::ContextSwitch() :
-    m_context(nullptr),
-    m_popCount(0)
-{
-}
-
-ContextSwitch::~ContextSwitch()
-{
-}
-
 bool ContextSwitch::isStay() const
 {
     return m_popCount == 0 && !m_context && m_contextName.isEmpty() && m_defName.isEmpty();
diff --git a/src/lib/contextswitch_p.h b/src/lib/contextswitch_p.h
--- a/src/lib/contextswitch_p.h
+++ b/src/lib/contextswitch_p.h
@@ -28,8 +28,8 @@
 class ContextSwitch
 {
 public:
-    ContextSwitch();
-    ~ContextSwitch();
+    ContextSwitch() = default;
+    ~ContextSwitch() = default;
 
     bool isStay() const;
 
@@ -42,8 +42,8 @@
 private:
     QString m_defName;
     QString m_contextName;
-    Context *m_context;
-    int m_popCount;
+    Context *m_context = nullptr;
+    int m_popCount = 0;
 };
 }
 
diff --git a/src/lib/definition.cpp b/src/lib/definition.cpp
--- a/src/lib/definition.cpp
+++ b/src/lib/definition.cpp
@@ -43,14 +43,8 @@
 
 using namespace KSyntaxHighlighting;
 
-DefinitionData::DefinitionData() :
-    repo(nullptr),
-    delimiters(QStringLiteral("\t !%&()*+,-./:;<=>?[\\]^{|}~")), // must be sorted!
-    indentationBasedFolding(false),
-    caseSensitive(Qt::CaseSensitive),
-    version(0.0f),
-    priority(0),
-    hidden(false)
+DefinitionData::DefinitionData()
+    : delimiters(QStringLiteral("\t !%&()*+,-./:;<=>?[\\]^{|}~")) // must be sorted!
 {
 }
 
diff --git a/src/lib/definition_p.h b/src/lib/definition_p.h
--- a/src/lib/definition_p.h
+++ b/src/lib/definition_p.h
@@ -69,12 +69,12 @@
 
     DefinitionRef q;
 
-    Repository *repo;
+    Repository *repo = nullptr;
     QHash<QString, KeywordList> keywordLists;
     QVector<Context*> contexts;
     QHash<QString, Format> formats;
     QString delimiters;
-    bool indentationBasedFolding;
+    bool indentationBasedFolding = false;
     QStringList foldingIgnoreList;
 
     QString fileName;
@@ -86,10 +86,10 @@
     QString license;
     QVector<QString> mimetypes;
     QVector<QString> extensions;
-    Qt::CaseSensitivity caseSensitive;
-    int version;
-    int priority;
-    bool hidden;
+    Qt::CaseSensitivity caseSensitive = Qt::CaseSensitive;
+    int version = 0;
+    int priority = 0;
+    bool hidden = false;
 };
 }
 
diff --git a/src/lib/format.cpp b/src/lib/format.cpp
--- a/src/lib/format.cpp
+++ b/src/lib/format.cpp
@@ -46,13 +46,6 @@
     return static_cast<Theme::TextStyle>(value);
 }
 
-FormatPrivate::FormatPrivate()
-    : defaultStyle(Theme::Normal)
-    , id(0)
-    , spellCheck(true)
-{
-}
-
 FormatPrivate* FormatPrivate::get(const Format &format)
 {
     return format.d.data();
diff --git a/src/lib/format_p.h b/src/lib/format_p.h
--- a/src/lib/format_p.h
+++ b/src/lib/format_p.h
@@ -30,18 +30,18 @@
 class FormatPrivate : public QSharedData
 {
 public:
-    FormatPrivate();
+    FormatPrivate() = default;
     static FormatPrivate* get(const Format &format);
 
     TextStyleData styleOverride(const Theme &theme) const;
     void load(QXmlStreamReader &reader);
 
     DefinitionRef definition;
     QString name;
     TextStyleData style;
-    Theme::TextStyle defaultStyle;
-    quint16 id;
-    bool spellCheck;
+    Theme::TextStyle defaultStyle = Theme::Normal;
+    quint16 id = 0;
+    bool spellCheck = true;
 };
 
 }
diff --git a/src/lib/keywordlist.cpp b/src/lib/keywordlist.cpp
--- a/src/lib/keywordlist.cpp
+++ b/src/lib/keywordlist.cpp
@@ -22,15 +22,6 @@
 
 using namespace KSyntaxHighlighting;
 
-KeywordList::KeywordList() :
-    m_caseSensitive(Qt::CaseSensitive)
-{
-}
-
-KeywordList::~KeywordList()
-{
-}
-
 bool KeywordList::isEmpty() const
 {
     return m_keywords.isEmpty();
diff --git a/src/lib/keywordlist_p.h b/src/lib/keywordlist_p.h
--- a/src/lib/keywordlist_p.h
+++ b/src/lib/keywordlist_p.h
@@ -29,8 +29,8 @@
 class KeywordList
 {
 public:
-    KeywordList();
-    ~KeywordList();
+    KeywordList() = default;
+    ~KeywordList() = default;
 
     bool isEmpty() const;
 
@@ -48,7 +48,7 @@
     QString m_name;
     QSet<QString> m_keywords;
     mutable QSet<QString> m_lowerCaseKeywords;
-    Qt::CaseSensitivity m_caseSensitive;
+    Qt::CaseSensitivity m_caseSensitive = Qt::CaseSensitive;
 };
 }
 
diff --git a/src/lib/matchresult.cpp b/src/lib/matchresult.cpp
--- a/src/lib/matchresult.cpp
+++ b/src/lib/matchresult.cpp
@@ -19,10 +19,9 @@
 
 using namespace KSyntaxHighlighting;
 
-MatchResult::MatchResult(int offset, const QStringList &captures) :
-    m_captures(captures),
-    m_offset(offset),
-    m_skipOffset(0)
+MatchResult::MatchResult(int offset, const QStringList &captures)
+    : m_captures(captures)
+    , m_offset(offset)
 {
 }
 
diff --git a/src/lib/matchresult_p.h b/src/lib/matchresult_p.h
--- a/src/lib/matchresult_p.h
+++ b/src/lib/matchresult_p.h
@@ -35,7 +35,7 @@
 private:
     QStringList m_captures;
     int m_offset;
-    int m_skipOffset;
+    int m_skipOffset = 0;
 };
 }
 
diff --git a/src/lib/repository.cpp b/src/lib/repository.cpp
--- a/src/lib/repository.cpp
+++ b/src/lib/repository.cpp
@@ -41,12 +41,6 @@
     Q_INIT_RESOURCE(syntax_data);
 }
 
-RepositoryPrivate::RepositoryPrivate() :
-    m_foldingRegionId(0),
-    m_formatId(0)
-{
-}
-
 RepositoryPrivate* RepositoryPrivate::get(Repository *repo)
 {
     return repo->d.get();
diff --git a/src/lib/repository_p.h b/src/lib/repository_p.h
--- a/src/lib/repository_p.h
+++ b/src/lib/repository_p.h
@@ -32,13 +32,14 @@
 class RepositoryPrivate
 {
 public:
-    RepositoryPrivate();
+    RepositoryPrivate() = default;
 
     static RepositoryPrivate* get(Repository *repo);
 
     void load(Repository *repo);
     void loadSyntaxFolder(Repository *repo, const QString &path);
     bool loadSyntaxFolderFromIndex(Repository *repo, const QString &path);
+
     void addDefinition(const Definition &def);
 
     void loadThemeFolder(const QString &path);
@@ -55,8 +56,8 @@
     QVector<Theme> m_themes;
 
     QHash<QPair<QString, QString>, quint16> m_foldingRegionIds;
-    quint16 m_foldingRegionId;
-    quint16 m_formatId;
+    quint16 m_foldingRegionId = 0;
+    quint16 m_formatId = 0;
 };
 }
 
diff --git a/src/lib/rule.cpp b/src/lib/rule.cpp
--- a/src/lib/rule.cpp
+++ b/src/lib/rule.cpp
@@ -85,18 +85,6 @@
     return result;
 }
 
-Rule::Rule() :
-    m_column(-1),
-    m_firstNonSpace(false),
-    m_lookAhead(false),
-    m_dynamic(false)
-{
-}
-
-Rule::~Rule()
-{
-}
-
 Definition Rule::definition() const
 {
     return m_def.definition();
diff --git a/src/lib/rule_p.h b/src/lib/rule_p.h
--- a/src/lib/rule_p.h
+++ b/src/lib/rule_p.h
@@ -38,8 +38,8 @@
 class Rule
 {
 public:
-    Rule();
-    virtual ~Rule();
+    Rule() = default;
+    virtual ~Rule() = default;
 
     typedef std::shared_ptr<Rule> Ptr;
 
@@ -76,12 +76,12 @@
     QString m_attribute;
     ContextSwitch m_context;
     QVector<Rule::Ptr> m_subRules;
-    int m_column;
+    int m_column = -1;
     FoldingRegion m_beginRegion;
     FoldingRegion m_endRegion;
-    bool m_firstNonSpace;
-    bool m_lookAhead;
-    bool m_dynamic;
+    bool m_firstNonSpace = false;
+    bool m_lookAhead = false;
+    bool m_dynamic = false;
 };
 
 
diff --git a/src/lib/state.cpp b/src/lib/state.cpp
--- a/src/lib/state.cpp
+++ b/src/lib/state.cpp
@@ -24,11 +24,6 @@
 
 using namespace KSyntaxHighlighting;
 
-StateData::StateData() :
-    m_defData(nullptr)
-{
-}
-
 StateData* StateData::get(State &state)
 {
     state.d.detach();
diff --git a/src/lib/state_p.h b/src/lib/state_p.h
--- a/src/lib/state_p.h
+++ b/src/lib/state_p.h
@@ -34,7 +34,7 @@
 class StateData : public QSharedData
 {
 public:
-    StateData();
+    StateData() = default;
     static StateData* get(State &state);
 
     bool isEmpty() const;
@@ -45,7 +45,7 @@
     Context* topContext() const;
     QStringList topCaptures() const;
 
-    DefinitionData *m_defData;
+    DefinitionData *m_defData = nullptr;
 private:
     friend class State;
     QStack<Context*> m_contextStack;
diff --git a/src/lib/textstyledata_p.h b/src/lib/textstyledata_p.h
--- a/src/lib/textstyledata_p.h
+++ b/src/lib/textstyledata_p.h
@@ -27,11 +27,7 @@
 public:
     // Constructor initializing all data.
     TextStyleData()
-        : textColor(0x0)
-        , backgroundColor(0x0)
-        , selectedTextColor(0x0)
-        , selectedBackgroundColor(0x0)
-        , bold(false)
+        : bold(false)
         , italic(false)
         , underline(false)
         , strikeThrough(false)
@@ -41,10 +37,10 @@
         , hasStrikeThrough(false)
     {}
 
-    QRgb textColor;
-    QRgb backgroundColor;
-    QRgb selectedTextColor;
-    QRgb selectedBackgroundColor;
+    QRgb textColor = 0x0;
+    QRgb backgroundColor = 0x0;
+    QRgb selectedTextColor = 0x0;
+    QRgb selectedBackgroundColor = 0x0;
     bool bold :1;
     bool italic :1;
     bool underline :1;
diff --git a/src/lib/themedata.cpp b/src/lib/themedata.cpp
--- a/src/lib/themedata.cpp
+++ b/src/lib/themedata.cpp
@@ -36,7 +36,6 @@
 }
 
 ThemeData::ThemeData()
-    : m_revision(0)
 {
     memset(m_editorColors, 0, sizeof(m_editorColors));
 }
diff --git a/src/lib/themedata_p.h b/src/lib/themedata_p.h
--- a/src/lib/themedata_p.h
+++ b/src/lib/themedata_p.h
@@ -136,7 +136,7 @@
     TextStyleData textStyleOverride(const QString &definitionName, const QString &attributeName) const;
 
 private:
-    int m_revision;
+    int m_revision = 0;
     QString m_name;
 
     //! Path to the file where the theme came from.