diff --git a/conf/editannottooldialog.cpp b/conf/editannottooldialog.cpp
index cf79d83c9..64a01ab59 100644
--- a/conf/editannottooldialog.cpp
+++ b/conf/editannottooldialog.cpp
@@ -1,3 +1,12 @@
+/***************************************************************************
+ *   Copyright (C) 2012 by Fabio D'Urso <fabiodurso@hotmail.it>            *
+ *   Copyright (C) 2015 by Laurent Montel <montel@kde.org>                 *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ ***************************************************************************/
 
 #include "editannottooldialog.h"
 
diff --git a/conf/editannottooldialog.h b/conf/editannottooldialog.h
index 23372b17d..c5794e56e 100644
--- a/conf/editannottooldialog.h
+++ b/conf/editannottooldialog.h
@@ -43,7 +43,7 @@ class EditAnnotToolDialog : public QDialog
             ToolStamp
         };
 
-        EditAnnotToolDialog( QWidget *parent = nullptr, const QDomElement &initialState = QDomElement() );
+        explicit EditAnnotToolDialog( QWidget *parent = nullptr, const QDomElement &initialState = QDomElement() );
         ~EditAnnotToolDialog();
         QString name() const;
         QDomDocument toolXml() const;
diff --git a/conf/widgetannottools.cpp b/conf/widgetannottools.cpp
index f94278a8e..74992374e 100644
--- a/conf/widgetannottools.cpp
+++ b/conf/widgetannottools.cpp
@@ -14,7 +14,7 @@
 #include <klocalizedstring.h>
 
 
-#include <QtWidgets/QApplication>
+#include <QApplication>
 #include <QHBoxLayout>
 #include <QListWidget>
 #include <QListWidgetItem>
diff --git a/core/action.h b/core/action.h
index 0b3ad370d..019df8850 100644
--- a/core/action.h
+++ b/core/action.h
@@ -237,7 +237,7 @@ class OKULARCORE_EXPORT ExecuteAction : public Action
 
 /**
  * The Browse action browses an url by opening a web browser or
- * email client, depedning on the url protocol (e.g. http, mailto, etc.).
+ * email client, depending on the url protocol (e.g. http, mailto, etc.).
  */
 class OKULARCORE_EXPORT BrowseAction : public Action
 {
@@ -247,7 +247,7 @@ class OKULARCORE_EXPORT BrowseAction : public Action
          *
          * @param url The url to browse.
          */
-        BrowseAction( const QUrl &url );
+        explicit BrowseAction( const QUrl &url );
 
         /**
          * Destroys the browse action.
@@ -461,7 +461,7 @@ class OKULARCORE_EXPORT MovieAction : public Action
         /**
          * Creates a new movie action.
          */
-        MovieAction( OperationType operation );
+        explicit MovieAction( OperationType operation );
 
         /**
          * Destroys the movie action.
diff --git a/core/annotations.h b/core/annotations.h
index 5c9397cb1..474fa73f8 100644
--- a/core/annotations.h
+++ b/core/annotations.h
@@ -781,7 +781,7 @@ class OKULARCORE_EXPORT TextAnnotation : public Annotation
         /**
          * Creates a new text annotation from the xml @p description
          */
-        TextAnnotation( const QDomNode &description );
+        explicit TextAnnotation( const QDomNode &description );
 
         /**
          * Destroys the text annotation.
@@ -1054,7 +1054,7 @@ class OKULARCORE_EXPORT GeomAnnotation : public Annotation
         /**
          * Creates a new geometrical annotation from the xml @p description
          */
-        GeomAnnotation( const QDomNode &description );
+        explicit GeomAnnotation( const QDomNode &description );
 
         /**
          * Destroys the geometrical annotation.
@@ -1296,7 +1296,7 @@ class OKULARCORE_EXPORT InkAnnotation : public Annotation
         /**
          * Creates a new ink annotation from the xml @p description
          */
-        InkAnnotation( const QDomNode &description );
+        explicit InkAnnotation( const QDomNode &description );
 
         /**
          * Destroys the ink annotation.
@@ -1458,7 +1458,7 @@ class OKULARCORE_EXPORT SoundAnnotation : public Annotation
         /**
          * Creates a new sound annotation from the xml @p description
          */
-        SoundAnnotation( const QDomNode &description );
+        explicit SoundAnnotation( const QDomNode &description );
         /**
          * Destroys the sound annotation.
          */
@@ -1518,7 +1518,7 @@ class OKULARCORE_EXPORT MovieAnnotation : public Annotation
         /**
          * Creates a new movie annotation from the xml @p description
          */
-        MovieAnnotation( const QDomNode &description );
+        explicit MovieAnnotation( const QDomNode &description );
         /**
          * Destroys the movie annotation.
          */
@@ -1565,7 +1565,7 @@ class OKULARCORE_EXPORT ScreenAnnotation : public Annotation
         /**
          * Creates a new screen annotation from the xml @p description
          */
-        ScreenAnnotation( const QDomNode &description );
+        explicit ScreenAnnotation( const QDomNode &description );
 
         /**
          * Destroys the screen annotation.
@@ -1634,7 +1634,7 @@ class OKULARCORE_EXPORT WidgetAnnotation : public Annotation
         /**
          * Creates a new widget annotation from the xml @p description
          */
-        WidgetAnnotation( const QDomNode &description );
+        explicit WidgetAnnotation( const QDomNode &description );
 
         /**
          * Destroys the widget annotation.
@@ -1689,7 +1689,7 @@ class OKULARCORE_EXPORT RichMediaAnnotation : public Annotation
         /**
          * Creates a new rich media annotation from the xml @p description
          */
-        RichMediaAnnotation( const QDomNode &description );
+        explicit RichMediaAnnotation( const QDomNode &description );
 
         /**
          * Destroys the rich media annotation.
diff --git a/core/area.h b/core/area.h
index 964f9da65..5f11aea0b 100644
--- a/core/area.h
+++ b/core/area.h
@@ -448,7 +448,7 @@ class OKULARCORE_EXPORT AnnotationObjectRect : public ObjectRect
          * Creates a new annotation object rectangle with the
          * given @p annotation.
          */
-        AnnotationObjectRect( Annotation *annotation );
+        explicit AnnotationObjectRect( Annotation *annotation );
 
         /**
          * Destroys the annotation object rectangle.
@@ -871,7 +871,7 @@ class HighlightAreaRect : public RegularAreaRect
          * Creates a new highlight area rect with the coordinates of
          * the given @p area.
          */
-        HighlightAreaRect( const RegularAreaRect *area = nullptr );
+        explicit HighlightAreaRect( const RegularAreaRect *area = nullptr );
 
         /**
          * The search ID of the highlight owner.
diff --git a/core/audioplayer_p.h b/core/audioplayer_p.h
index bc325f7cc..1b2ea58f6 100644
--- a/core/audioplayer_p.h
+++ b/core/audioplayer_p.h
@@ -26,7 +26,7 @@ class AudioPlayer;
 class AudioPlayerPrivate
 {
 public:
-    AudioPlayerPrivate( AudioPlayer * qq );
+    explicit AudioPlayerPrivate( AudioPlayer * qq );
 
     ~AudioPlayerPrivate();
 
diff --git a/core/document_p.h b/core/document_p.h
index c47229118..792bec813 100644
--- a/core/document_p.h
+++ b/core/document_p.h
@@ -86,7 +86,7 @@ Q_DECLARE_FLAGS(LoadDocumentInfoFlags, LoadDocumentInfoFlag)
 class DocumentPrivate
 {
     public:
-        DocumentPrivate( Document *parent )
+        explicit DocumentPrivate( Document *parent )
           : m_parent( parent ),
             m_tempFile( nullptr ),
             m_docSize( -1 ),
diff --git a/core/form_p.h b/core/form_p.h
index 7e8389bf2..cbba06272 100644
--- a/core/form_p.h
+++ b/core/form_p.h
@@ -22,7 +22,7 @@ class FormField;
 class FormFieldPrivate
 {
     public:
-        FormFieldPrivate( FormField::FieldType type );
+        explicit FormFieldPrivate( FormField::FieldType type );
         virtual ~FormFieldPrivate();
 
         void setDefault();
diff --git a/core/generator.h b/core/generator.h
index ceaa43ced..b989a55de 100644
--- a/core/generator.h
+++ b/core/generator.h
@@ -221,7 +221,7 @@ class OKULARCORE_EXPORT Generator : public QObject
         /**
          * Creates a new generator.
          */
-        Generator(QObject* parent = nullptr, const QVariantList& args = QVariantList());
+        explicit Generator(QObject* parent = nullptr, const QVariantList& args = QVariantList());
 
         /**
          * Destroys the generator.
@@ -781,7 +781,7 @@ class OKULARCORE_EXPORT TextRequest
         /**
          * Creates a new text request.
          */
-        TextRequest( Page *page );
+        explicit TextRequest( Page *page );
 
         TextRequest();
 
diff --git a/core/generator_p.h b/core/generator_p.h
index 62858a9eb..239be0a79 100644
--- a/core/generator_p.h
+++ b/core/generator_p.h
@@ -114,7 +114,7 @@ class PixmapGenerationThread : public QThread
     Q_OBJECT
 
     public:
-        PixmapGenerationThread( Generator *generator );
+        explicit PixmapGenerationThread( Generator *generator );
 
         void startGeneration( PixmapRequest *request, bool calcBoundingRect );
 
@@ -142,7 +142,7 @@ class TextPageGenerationThread : public QThread
     Q_OBJECT
 
     public:
-        TextPageGenerationThread( Generator *generator );
+        explicit TextPageGenerationThread( Generator *generator );
 
         void endGeneration();
 
diff --git a/core/script/event_p.h b/core/script/event_p.h
index 928833f08..eadd481d2 100644
--- a/core/script/event_p.h
+++ b/core/script/event_p.h
@@ -70,7 +70,7 @@ class Event
             PageClose,       /// < Not implemented.
         };
 
-        Event(EventType type);
+        explicit Event(EventType type);
 
         /** One of the defined EventTypes */
         EventType eventType() const;
diff --git a/core/script/executor_kjs_p.h b/core/script/executor_kjs_p.h
index a193391fe..6d1462ef3 100644
--- a/core/script/executor_kjs_p.h
+++ b/core/script/executor_kjs_p.h
@@ -21,7 +21,7 @@ class Event;
 class ExecutorKJS
 {
     public:
-        ExecutorKJS( DocumentPrivate *doc );
+        explicit ExecutorKJS( DocumentPrivate *doc );
         ~ExecutorKJS();
 
         void execute( const QString &script, Event *event );
diff --git a/core/textdocumentgenerator_p.h b/core/textdocumentgenerator_p.h
index 1a4b869c5..e5fb0b34a 100644
--- a/core/textdocumentgenerator_p.h
+++ b/core/textdocumentgenerator_p.h
@@ -115,7 +115,7 @@ class TextDocumentGeneratorPrivate : public GeneratorPrivate
     friend class TextDocumentConverter;
 
     public:
-        TextDocumentGeneratorPrivate( TextDocumentConverter *converter )
+        explicit TextDocumentGeneratorPrivate( TextDocumentConverter *converter )
             : mConverter( converter ), mDocument( nullptr ), mGeneralSettings( nullptr )
         {
         }
diff --git a/core/textdocumentsettings.h b/core/textdocumentsettings.h
index 50992a9ff..c295ccc81 100644
--- a/core/textdocumentsettings.h
+++ b/core/textdocumentsettings.h
@@ -84,7 +84,7 @@ class OKULARCORE_EXPORT TextDocumentSettingsWidget : public QWidget
     Q_OBJECT
 
     public:
-        TextDocumentSettingsWidget( QWidget *parent = nullptr );
+        explicit TextDocumentSettingsWidget( QWidget *parent = nullptr );
         virtual ~TextDocumentSettingsWidget();
 
         void addRow( const QString& labelText, QWidget *widget );
diff --git a/core/textdocumentsettings_p.h b/core/textdocumentsettings_p.h
index 998156b0f..b69e3d337 100644
--- a/core/textdocumentsettings_p.h
+++ b/core/textdocumentsettings_p.h
@@ -23,7 +23,7 @@ class TextDocumentSettingsWidgetPrivate
          * @note the private class won't take ownership of the ui, so you
          *       must delete it yourself
          */
-        TextDocumentSettingsWidgetPrivate(Ui_TextDocumentSettings *ui)
+        explicit TextDocumentSettingsWidgetPrivate(Ui_TextDocumentSettings *ui)
             : mUi(ui)
         {}
 
@@ -36,7 +36,7 @@ class TextDocumentSettingsPrivate : public QObject
     Q_OBJECT
 
     public:
-        TextDocumentSettingsPrivate(QObject *parent)
+        explicit TextDocumentSettingsPrivate(QObject *parent)
             : QObject(parent)
         {}
 
diff --git a/extensions.h b/extensions.h
index e61340aeb..9d6b172ef 100644
--- a/extensions.h
+++ b/extensions.h
@@ -24,7 +24,7 @@ class BrowserExtension : public KParts::BrowserExtension
     Q_OBJECT
 
     public:
-        BrowserExtension(Part*);
+        explicit BrowserExtension(Part*);
 
     public Q_SLOTS:
         // Automatically detected by the host.
@@ -39,7 +39,7 @@ class OkularLiveConnectExtension : public KParts::LiveConnectExtension
     Q_OBJECT
 
     public:
-        OkularLiveConnectExtension( Part *parent );
+        explicit OkularLiveConnectExtension( Part *parent );
 
         // from LiveConnectExtension
         bool get( const unsigned long objid, const QString &field, Type &type,
diff --git a/generators/djvu/kdjvu.h b/generators/djvu/kdjvu.h
index 9a5998d64..d111e633e 100644
--- a/generators/djvu/kdjvu.h
+++ b/generators/djvu/kdjvu.h
@@ -157,7 +157,7 @@ class KDjVu
                 bool inlineText() const;
 
             private:
-                TextAnnotation( miniexp_t anno );
+                explicit TextAnnotation( miniexp_t anno );
                 QSize m_size;
                 bool m_inlineText;
         };
@@ -179,7 +179,7 @@ class KDjVu
                 void setWidth( int width );
 
             private:
-                LineAnnotation( miniexp_t anno );
+                explicit LineAnnotation( miniexp_t anno );
                 QPoint m_point2;
                 bool m_isArrow;
                 miniexp_t m_width;
diff --git a/generators/epub/epubdocument.h b/generators/epub/epubdocument.h
index e823e3d06..2bd922681 100644
--- a/generators/epub/epubdocument.h
+++ b/generators/epub/epubdocument.h
@@ -24,7 +24,7 @@ namespace Epub {
     Q_OBJECT
 
   public:
-    EpubDocument(const QString &fileName);
+    explicit EpubDocument(const QString &fileName);
     bool isValid();
     ~EpubDocument();
     struct epub *getEpub();
diff --git a/generators/fictionbook/document.h b/generators/fictionbook/document.h
index de0b83260..1fee7e9cd 100644
--- a/generators/fictionbook/document.h
+++ b/generators/fictionbook/document.h
@@ -20,7 +20,7 @@ namespace FictionBook {
 class Document
 {
     public:
-        Document( const QString &fileName );
+        explicit Document( const QString &fileName );
 
         bool open();
 
diff --git a/generators/mobipocket/mobidocument.h b/generators/mobipocket/mobidocument.h
index de4398449..d589c942f 100644
--- a/generators/mobipocket/mobidocument.h
+++ b/generators/mobipocket/mobidocument.h
@@ -24,7 +24,7 @@ namespace Mobi {
   class MobiDocument : public QTextDocument {
       
   public:
-    MobiDocument(const QString &fileName);  
+    explicit MobiDocument(const QString &fileName);  
     ~MobiDocument();   
     
     Mobipocket::Document* mobi() const { return doc; }
diff --git a/generators/ooo/document.h b/generators/ooo/document.h
index 9c6bc97f6..bb681a7d9 100644
--- a/generators/ooo/document.h
+++ b/generators/ooo/document.h
@@ -21,7 +21,7 @@ namespace OOO {
 class Document
 {
   public:
-    Document( const QString &fileName );
+    explicit Document( const QString &fileName );
     ~Document();
 
     bool open( const QString &password );
diff --git a/generators/ooo/formatproperty.h b/generators/ooo/formatproperty.h
index 268066906..3b13f4d6e 100644
--- a/generators/ooo/formatproperty.h
+++ b/generators/ooo/formatproperty.h
@@ -76,7 +76,7 @@ class TextFormatProperty
 {
   public:
     TextFormatProperty();
-    TextFormatProperty( const StyleInformation *information );
+    explicit TextFormatProperty( const StyleInformation *information );
 
     void apply( QTextCharFormat *format ) const;
 
@@ -155,7 +155,7 @@ class ListFormatProperty
     };
 
     ListFormatProperty();
-    ListFormatProperty( Type type );
+    explicit ListFormatProperty( Type type );
 
     void apply( QTextListFormat *format, int level ) const;
 
@@ -202,7 +202,7 @@ class StyleFormatProperty
 {
   public:
     StyleFormatProperty();
-    StyleFormatProperty( const StyleInformation *information );
+    explicit StyleFormatProperty( const StyleInformation *information );
 
     void applyBlock( QTextBlockFormat *format ) const;
     void applyText( QTextCharFormat *format ) const;
diff --git a/generators/ooo/manifest.h b/generators/ooo/manifest.h
index fb5565664..b251b65fe 100644
--- a/generators/ooo/manifest.h
+++ b/generators/ooo/manifest.h
@@ -45,7 +45,7 @@ class ManifestEntry
     /**
        Create a new manifest entry
     */
-    ManifestEntry( const QString &fileName );
+    explicit ManifestEntry( const QString &fileName );
 
     /**
        Set the mimetype of the file.
diff --git a/generators/poppler/formfields.h b/generators/poppler/formfields.h
index 46e95c45a..9f39dfbef 100644
--- a/generators/poppler/formfields.h
+++ b/generators/poppler/formfields.h
@@ -16,7 +16,7 @@
 class PopplerFormFieldButton : public Okular::FormFieldButton
 {
     public:
-        PopplerFormFieldButton( Poppler::FormFieldButton * field );
+        explicit PopplerFormFieldButton( Poppler::FormFieldButton * field );
         virtual ~PopplerFormFieldButton();
 
         // inherited from Okular::FormField
@@ -46,7 +46,7 @@ class PopplerFormFieldButton : public Okular::FormFieldButton
 class PopplerFormFieldText : public Okular::FormFieldText
 {
     public:
-        PopplerFormFieldText( Poppler::FormFieldText * field );
+        explicit PopplerFormFieldText( Poppler::FormFieldText * field );
         virtual ~PopplerFormFieldText();
 
         // inherited from Okular::FormField
@@ -79,7 +79,7 @@ class PopplerFormFieldText : public Okular::FormFieldText
 class PopplerFormFieldChoice : public Okular::FormFieldChoice
 {
     public:
-        PopplerFormFieldChoice( Poppler::FormFieldChoice * field );
+        explicit PopplerFormFieldChoice( Poppler::FormFieldChoice * field );
         virtual ~PopplerFormFieldChoice();
 
         // inherited from Okular::FormField
diff --git a/generators/txt/document.h b/generators/txt/document.h
index adfcbab52..83dac896c 100644
--- a/generators/txt/document.h
+++ b/generators/txt/document.h
@@ -19,7 +19,7 @@ namespace Txt
         Q_OBJECT
 
         public:
-            Document( const QString &fileName );
+            explicit Document( const QString &fileName );
             ~Document();
 
         private:
diff --git a/generators/xps/generator_xps.h b/generators/xps/generator_xps.h
index 4b99437aa..f122e38a9 100644
--- a/generators/xps/generator_xps.h
+++ b/generators/xps/generator_xps.h
@@ -110,7 +110,7 @@ class XpsFile;
 class XpsHandler: public QXmlDefaultHandler
 {
 public:
-    XpsHandler( XpsPage *page );
+    explicit XpsHandler( XpsPage *page );
     ~XpsHandler();
 
     bool startElement( const QString & nameSpace,
diff --git a/mobile/components/documentitem.cpp b/mobile/components/documentitem.cpp
index e674d0015..57461f6c2 100644
--- a/mobile/components/documentitem.cpp
+++ b/mobile/components/documentitem.cpp
@@ -19,7 +19,7 @@
 
 #include "documentitem.h"
 
-#include <QtQml>
+#include <QtQml> // krazy:exclude=includes
 #include <QMimeDatabase>
 
 #include <core/document_p.h>
diff --git a/mobile/components/documentitem.h b/mobile/components/documentitem.h
index 2c864811c..180bbb910 100644
--- a/mobile/components/documentitem.h
+++ b/mobile/components/documentitem.h
@@ -169,7 +169,7 @@ class Observer : public QObject, public Okular::DocumentObserver
     Q_OBJECT
 
 public:
-    Observer(DocumentItem *parent);
+    explicit Observer(DocumentItem *parent);
     ~Observer();
 
     // inherited from DocumentObserver
diff --git a/part.h b/part.h
index ad963a90b..981d96661 100644
--- a/part.h
+++ b/part.h
@@ -23,7 +23,7 @@
 #include <QList>
 #include <QPointer>
 #include <QProcess>
-#include <QtDBus>
+#include <QtDBus> // krazy:exclude=includes
 #include <QUrl>
 
 #include <KCompressionDevice>
diff --git a/shell/shell.h b/shell/shell.h
index a66c60675..1f16cb2fb 100644
--- a/shell/shell.h
+++ b/shell/shell.h
@@ -20,9 +20,9 @@
 #include <kparts/readwritepart.h>
 #include <QMimeType>
 #include <QMimeDatabase>
-#include <qaction.h>
+#include <QAction>
 
-#include <QtDBus>
+#include <QtDBus> // krazy:exclude=includes
 
 class KRecentFilesAction;
 class KToggleAction;
diff --git a/ui/annotationtools.h b/ui/annotationtools.h
index 1f7aa97cf..bd048029f 100644
--- a/ui/annotationtools.h
+++ b/ui/annotationtools.h
@@ -32,7 +32,7 @@ class Page;
 class AnnotatorEngine
 {
     public:
-        AnnotatorEngine( const QDomElement & engineElement );
+        explicit AnnotatorEngine( const QDomElement & engineElement );
         virtual ~AnnotatorEngine();
 
         // enum definitions
@@ -87,7 +87,7 @@ class SmoothPathEngine
     : public AnnotatorEngine
 {
     public:
-        SmoothPathEngine( const QDomElement & engineElement );
+        explicit SmoothPathEngine( const QDomElement & engineElement );
 
         QRect event( EventType type, Button button, double nX, double nY, double xScale, double yScale, const Okular::Page * /*page*/ ) override;
 
diff --git a/ui/annotationwidgets.h b/ui/annotationwidgets.h
index 13442ce47..ae5e427e7 100644
--- a/ui/annotationwidgets.h
+++ b/ui/annotationwidgets.h
@@ -72,7 +72,7 @@ class AnnotationWidget
     Q_OBJECT
 
 public:
-    AnnotationWidget( Okular::Annotation * ann );
+    explicit AnnotationWidget( Okular::Annotation * ann );
     virtual ~AnnotationWidget();
 
     virtual Okular::Annotation::SubType annotationType() const;
diff --git a/ui/embeddedfilesdialog.cpp b/ui/embeddedfilesdialog.cpp
index e2901923d..ea162b957 100644
--- a/ui/embeddedfilesdialog.cpp
+++ b/ui/embeddedfilesdialog.cpp
@@ -183,7 +183,7 @@ void EmbeddedFilesDialog::viewFile( Okular::EmbeddedFile* ef )
 		+ QDir::separator()
 		+ fileInfo.baseName()
 		+ ".XXXXXX"
-		+ (fileInfo.completeSuffix().isEmpty() ? QString("") : "." + fileInfo.completeSuffix())
+		+ (fileInfo.completeSuffix().isEmpty() ? QString("") : "." + fileInfo.completeSuffix()) // krazy:exclude=doublequote_chars
 	);
 	GuiUtils::writeEmbeddedFile( ef, this, *tmpFile );
 
diff --git a/ui/formwidgets.h b/ui/formwidgets.h
index 218137172..f0206c3bb 100644
--- a/ui/formwidgets.h
+++ b/ui/formwidgets.h
@@ -54,7 +54,7 @@ class FormWidgetsController : public QObject
     Q_OBJECT
 
     public:
-        FormWidgetsController( Okular::Document *doc );
+        explicit FormWidgetsController( Okular::Document *doc );
         virtual ~FormWidgetsController();
 
         void signalAction( Okular::Action *action );
diff --git a/ui/magnifierview.h b/ui/magnifierview.h
index 09f26f7db..cd24e1eb2 100644
--- a/ui/magnifierview.h
+++ b/ui/magnifierview.h
@@ -29,7 +29,7 @@ class MagnifierView : public QWidget, public Okular::DocumentObserver
   Q_OBJECT
 
   public:
-    MagnifierView( Okular::Document *document, QWidget *parent = nullptr );
+    explicit MagnifierView( Okular::Document *document, QWidget *parent = nullptr );
     ~MagnifierView();
 
     void notifySetup( const QVector< Okular::Page * > & pages, int setupFlags ) override;
diff --git a/ui/minibar.h b/ui/minibar.h
index d49007de1..0bf969ff0 100644
--- a/ui/minibar.h
+++ b/ui/minibar.h
@@ -32,7 +32,7 @@ class PagesEdit : public KLineEdit
     Q_OBJECT
 
     public:
-        PagesEdit( MiniBar * parent );
+        explicit PagesEdit( MiniBar * parent );
         void setText( const QString & ) override;
 
     protected:
@@ -54,7 +54,7 @@ class PageNumberEdit : public PagesEdit
     Q_OBJECT
 
     public:
-        PageNumberEdit( MiniBar * parent );
+        explicit PageNumberEdit( MiniBar * parent );
         void setPagesNumber( int pages );
 
     private:
@@ -65,7 +65,7 @@ class PageLabelEdit : public PagesEdit
 {
   Q_OBJECT
     public:
-        PageLabelEdit( MiniBar * parent );
+        explicit PageLabelEdit( MiniBar * parent );
         void setText( const QString & newText ) override;
         void setPageLabels( const QVector< Okular::Page * > & pageVector );
 
diff --git a/ui/pageitemdelegate.h b/ui/pageitemdelegate.h
index 4067db060..bbf0a802c 100644
--- a/ui/pageitemdelegate.h
+++ b/ui/pageitemdelegate.h
@@ -17,7 +17,7 @@ class PageItemDelegate : public QItemDelegate
     Q_OBJECT
 
     public:
-        PageItemDelegate( QObject * parent = nullptr );
+        explicit PageItemDelegate( QObject * parent = nullptr );
         virtual ~PageItemDelegate();
 
         static const int PageRole = 0x000f0001;
diff --git a/ui/pageviewutils.h b/ui/pageviewutils.h
index 6c3740927..3fabeb702 100644
--- a/ui/pageviewutils.h
+++ b/ui/pageviewutils.h
@@ -107,7 +107,7 @@ class PageViewMessage : public QWidget
     Q_OBJECT
 
     public:
-        PageViewMessage( QWidget * parent );
+        explicit PageViewMessage( QWidget * parent );
 
         enum Icon { None, Info, Warning, Error, Find, Annotation };
         void display( const QString & message, const QString & details = QString(), Icon icon = Info, int durationMs = 4000 );
diff --git a/ui/propertiesdialog.h b/ui/propertiesdialog.h
index dbf7ebd51..5abe394c3 100644
--- a/ui/propertiesdialog.h
+++ b/ui/propertiesdialog.h
@@ -56,7 +56,7 @@ class FontsListModel
   Q_OBJECT
 
   public:
-    FontsListModel( QObject * parent = nullptr );
+    explicit FontsListModel( QObject * parent = nullptr );
     virtual ~FontsListModel();
 
     // reimplementations from QAbstractTableModel
diff --git a/ui/sidebar.h b/ui/sidebar.h
index 3eb3b4639..1256a39a2 100644
--- a/ui/sidebar.h
+++ b/ui/sidebar.h
@@ -20,7 +20,7 @@ class OKULARPART_EXPORT Sidebar : public QWidget
 {
     Q_OBJECT
     public:
-        Sidebar( QWidget *parent = nullptr );
+        explicit Sidebar( QWidget *parent = nullptr );
         ~Sidebar();
 
         int addItem( QWidget *widget, const QIcon &icon, const QString &text );
diff --git a/ui/snapshottaker.h b/ui/snapshottaker.h
index 4f624b26c..ae4c71f51 100644
--- a/ui/snapshottaker.h
+++ b/ui/snapshottaker.h
@@ -21,7 +21,7 @@ class SnapshotTaker : public QObject
     Q_OBJECT
 
     public:
-        SnapshotTaker( const QUrl &url, QObject *parent = nullptr );
+        explicit SnapshotTaker( const QUrl &url, QObject *parent = nullptr );
         ~SnapshotTaker();
 
     Q_SIGNALS:
diff --git a/ui/thumbnaillist.h b/ui/thumbnaillist.h
index f2fd3b34b..0717c58c1 100644
--- a/ui/thumbnaillist.h
+++ b/ui/thumbnaillist.h
@@ -80,7 +80,7 @@ class ThumbnailsBox : public QWidget
     Q_OBJECT
 
     public:
-        ThumbnailsBox( QWidget * parent ) : QWidget( parent ) { QVBoxLayout *vbox = new QVBoxLayout(this); vbox->setMargin(0); vbox->setSpacing(0);}
+        explicit ThumbnailsBox( QWidget * parent ) : QWidget( parent ) { QVBoxLayout *vbox = new QVBoxLayout(this); vbox->setMargin(0); vbox->setSpacing(0);}
         QSize sizeHint() const override { return QSize(); }
 };
 
diff --git a/ui/toolaction.h b/ui/toolaction.h
index 2070ede0e..3f42bcc21 100644
--- a/ui/toolaction.h
+++ b/ui/toolaction.h
@@ -22,7 +22,7 @@ class ToolAction : public KSelectAction
     Q_OBJECT
 
     public:
-        ToolAction( QObject *parent = nullptr );
+        explicit ToolAction( QObject *parent = nullptr );
         virtual ~ToolAction();
 
         void addAction( QAction *action );
diff --git a/ui/tts.h b/ui/tts.h
index 00d8c2e73..767ad4c89 100644
--- a/ui/tts.h
+++ b/ui/tts.h
@@ -17,7 +17,7 @@ class OkularTTS : public QObject
 {
     Q_OBJECT
     public:
-        OkularTTS( QObject *parent = nullptr );
+        explicit OkularTTS( QObject *parent = nullptr );
         ~OkularTTS();
 
         void say( const QString &text );