diff --git a/doc/pluginhowto/examples/loggermode/loggermodewidget.h b/doc/pluginhowto/examples/loggermode/loggermodewidget.h
index f05263f32fd1c04e1da394a9690f7ff20d9c5d23..09979cda7ebe70a4ea28057133dcf8b6a50c55c2 100644
--- a/doc/pluginhowto/examples/loggermode/loggermodewidget.h
+++ b/doc/pluginhowto/examples/loggermode/loggermodewidget.h
@@ -9,7 +9,7 @@ class LoggerModeWidget : public QWidget
     Q_OBJECT
 
 public:
-    LoggerModeWidget(const QString projectName, QWidget* parent = 0);
+    explicit LoggerModeWidget(const QString projectName, QWidget* parent = 0);
     ~LoggerModeWidget();
 
 public slots:
diff --git a/doc/pluginhowto/examples/wizard/itemmodelwizard/modelclasswizard.h b/doc/pluginhowto/examples/wizard/itemmodelwizard/modelclasswizard.h
index 2e02efe356c0bd17040a9062e46c4261ec10d24d..42716e099495042d0196d7b54ea5f99cf3c5f3d7 100644
--- a/doc/pluginhowto/examples/wizard/itemmodelwizard/modelclasswizard.h
+++ b/doc/pluginhowto/examples/wizard/itemmodelwizard/modelclasswizard.h
@@ -9,7 +9,7 @@ class ModelClassWizard : public Core::BaseFileWizard
     Q_OBJECT
 
 public:
-    ModelClassWizard(const Core::BaseFileWizardParameters &parameters, QObject *parent = 0);
+    explicit ModelClassWizard(const Core::BaseFileWizardParameters &parameters, QObject *parent = 0);
     ~ModelClassWizard();
 
     QWizard *createWizardDialog(QWidget *parent,
diff --git a/src/libs/aggregation/examples/text/main.h b/src/libs/aggregation/examples/text/main.h
index cc669811499bb3876efaaa33b6c6311b2469f55c..900cee8505433604f5da14b1bae7487ee9e3d95e 100644
--- a/src/libs/aggregation/examples/text/main.h
+++ b/src/libs/aggregation/examples/text/main.h
@@ -42,7 +42,7 @@ class MyMain : public QWidget
     Q_OBJECT
 
 public:
-    MyMain(QWidget *parent = 0, Qt::WFlags flags = 0);
+    explicit MyMain(QWidget *parent = 0, Qt::WFlags flags = 0);
     ~MyMain();
 
     void add(IComboEntry *obj);
diff --git a/src/libs/cplusplus/BackwardsScanner.h b/src/libs/cplusplus/BackwardsScanner.h
index 26b45f5667ccc1e8698de2dfdfb6f2f9cb9f5f4a..a2cb6e6ac3b72534975a4963072280dde523937a 100644
--- a/src/libs/cplusplus/BackwardsScanner.h
+++ b/src/libs/cplusplus/BackwardsScanner.h
@@ -41,9 +41,9 @@ class CPLUSPLUS_EXPORT BackwardsScanner
     enum { MAX_BLOCK_COUNT = 10 };
 
 public:
-    BackwardsScanner(const QTextCursor &cursor,
-                     int maxBlockCount = MAX_BLOCK_COUNT,
-                     const QString &suffix = QString());
+    explicit BackwardsScanner(const QTextCursor &cursor,
+                              int maxBlockCount = MAX_BLOCK_COUNT,
+                              const QString &suffix = QString());
 
     int startToken() const;
 
diff --git a/src/libs/cplusplus/PreprocessorClient.h b/src/libs/cplusplus/PreprocessorClient.h
index 649f6ddfe7730d53b927bff98aef9bfd5bb79bc4..b9d9145fce7ad7115256aaea1e5a4863d973a0e1 100644
--- a/src/libs/cplusplus/PreprocessorClient.h
+++ b/src/libs/cplusplus/PreprocessorClient.h
@@ -48,7 +48,7 @@ class CPLUSPLUS_EXPORT MacroArgumentReference
   unsigned _length;
 
 public:
-  MacroArgumentReference(unsigned position = 0, unsigned length = 0)
+  explicit MacroArgumentReference(unsigned position = 0, unsigned length = 0)
     : _position(position), _length(length)
   { }
 
diff --git a/src/libs/cplusplus/pp-macro-expander.h b/src/libs/cplusplus/pp-macro-expander.h
index f19be4111fa2d8c123a8c4b9bbade8a85f94c29b..2021c3f2fbacb8d725ce52bcafcf7dd257e158da 100644
--- a/src/libs/cplusplus/pp-macro-expander.h
+++ b/src/libs/cplusplus/pp-macro-expander.h
@@ -80,7 +80,7 @@ class MacroExpander
     const QByteArray *resolve_formal(const QByteArray &name);
 
 public:
-    MacroExpander(Environment *env, pp_frame *frame = 0, Client *client = 0, unsigned start_offset = 0);
+    explicit MacroExpander(Environment *env, pp_frame *frame = 0, Client *client = 0, unsigned start_offset = 0);
 
     const char *operator()(const char *first, const char *last,
                              QByteArray *result);
diff --git a/src/libs/extensionsystem/pluginview.h b/src/libs/extensionsystem/pluginview.h
index b1668b2304cb541d488a8d8b0fd4cd4d99c86fb8..740d52a8ffa0361cea76948be41434b09ffd8daf 100644
--- a/src/libs/extensionsystem/pluginview.h
+++ b/src/libs/extensionsystem/pluginview.h
@@ -58,7 +58,7 @@ class EXTENSIONSYSTEM_EXPORT PluginView : public QWidget
     Q_OBJECT
 
 public:
-    PluginView(PluginManager *manager, QWidget *parent = 0);
+    explicit PluginView(PluginManager *manager, QWidget *parent = 0);
     ~PluginView();
 
     PluginSpec *currentPlugin() const;
diff --git a/src/libs/qmljs/parser/qmljsast_p.h b/src/libs/qmljs/parser/qmljsast_p.h
index 1b9762ed5768375c0017a0a297f88219587d7020..7bab8f80f6462e27acc7bdb84c2bd1694b8909ef 100644
--- a/src/libs/qmljs/parser/qmljsast_p.h
+++ b/src/libs/qmljs/parser/qmljsast_p.h
@@ -272,7 +272,7 @@ class QML_PARSER_EXPORT UiFormal: public Node
 public:
     QMLJS_DECLARE_AST_NODE(UiFormal)
 
-    UiFormal(NameId *name, NameId *alias = 0)
+    explicit UiFormal(NameId *name, NameId *alias = 0)
       : name(name), alias(alias)
     { }
 
@@ -1762,7 +1762,7 @@ class QML_PARSER_EXPORT CaseBlock: public Node
 public:
     QMLJS_DECLARE_AST_NODE(CaseBlock)
 
-    CaseBlock(CaseClauses *c, DefaultClause *d = 0, CaseClauses *r = 0):
+    explicit CaseBlock(CaseClauses *c, DefaultClause *d = 0, CaseClauses *r = 0):
         clauses (c), defaultClause (d), moreClauses (r)
         { kind = K; }
 
diff --git a/src/libs/qmljs/parser/qmljsastfwd_p.h b/src/libs/qmljs/parser/qmljsastfwd_p.h
index 2c42fd9d8963e880194e369424b7c52d5cfab6a2..371739177cc011f2069e96bb76d3b67899a23129 100644
--- a/src/libs/qmljs/parser/qmljsastfwd_p.h
+++ b/src/libs/qmljs/parser/qmljsastfwd_p.h
@@ -64,7 +64,7 @@ namespace QmlJS { namespace AST {
 class SourceLocation
 {
 public:
-    SourceLocation(quint32 offset = 0, quint32 length = 0, quint32 line = 0, quint32 column = 0)
+    explicit SourceLocation(quint32 offset = 0, quint32 length = 0, quint32 line = 0, quint32 column = 0)
         : offset(offset), length(length),
           startLine(line), startColumn(column)
     { }
diff --git a/src/libs/qmljs/parser/qmljslexer_p.h b/src/libs/qmljs/parser/qmljslexer_p.h
index 8f95a904f44561b259e844b1df90c51606ba53fc..cf731c7bdb6dfe6ba614c9f05391e7fc7f6a8bd3 100644
--- a/src/libs/qmljs/parser/qmljslexer_p.h
+++ b/src/libs/qmljs/parser/qmljslexer_p.h
@@ -67,7 +67,7 @@ class NameId;
 class QML_PARSER_EXPORT Lexer
 {
 public:
-    Lexer(Engine *eng, bool tokenizeComments = false);
+    explicit Lexer(Engine *eng, bool tokenizeComments = false);
     ~Lexer();
 
     void setCode(const QString &c, int lineno);
diff --git a/src/libs/qmljsdebugclient/qdeclarativedebug_p.h b/src/libs/qmljsdebugclient/qdeclarativedebug_p.h
index ad616411b6901366744c2e0f6d594cb5a63780cc..982e581f690e23acb1073c077b10e126b86a5145 100644
--- a/src/libs/qmljsdebugclient/qdeclarativedebug_p.h
+++ b/src/libs/qmljsdebugclient/qdeclarativedebug_p.h
@@ -69,7 +69,7 @@ class QDeclarativeEngineDebug : public QObject
 {
 Q_OBJECT
 public:
-    QDeclarativeEngineDebug(QDeclarativeDebugConnection *, QObject * = 0);
+    explicit QDeclarativeEngineDebug(QDeclarativeDebugConnection *, QObject * = 0);
     ~QDeclarativeEngineDebug();
 
     QDeclarativeDebugPropertyWatch *addWatch(const QDeclarativeDebugPropertyReference &,
diff --git a/src/plugins/classview/classviewsymbollocation.h b/src/plugins/classview/classviewsymbollocation.h
index cc028bb002d49c9ba0f5c06d0054dd98ac526ab1..55f4dcbd46a2a905a5ce23d64857de9d9f4c0346 100644
--- a/src/plugins/classview/classviewsymbollocation.h
+++ b/src/plugins/classview/classviewsymbollocation.h
@@ -48,7 +48,7 @@ public:
     SymbolLocation();
 
     //! Constructor
-    SymbolLocation(QString file, int lineNumber = 0, int columnNumber = 0);
+    explicit SymbolLocation(QString file, int lineNumber = 0, int columnNumber = 0);
 
     inline const QString &fileName() const { return m_fileName; }
     inline int line() const { return m_line; }
diff --git a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
index b96cd54c20e1fbebdffce1e389cc054f6c4e09e7..573cc5026890908ab4ca2391931287967576b6b8 100644
--- a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
+++ b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
@@ -108,7 +108,7 @@ class ShadowBuildPage : public QWizardPage
 {
     Q_OBJECT
 public:
-    ShadowBuildPage(CMakeOpenProjectWizard *cmakeWizard, bool change = false);
+    explicit ShadowBuildPage(CMakeOpenProjectWizard *cmakeWizard, bool change = false);
 private slots:
     void buildDirectoryChanged();
 private:
@@ -121,7 +121,7 @@ class CMakeRunPage : public QWizardPage
     Q_OBJECT
 public:
     enum Mode { Initial, Update, Recreate, Change };
-    CMakeRunPage(CMakeOpenProjectWizard *cmakeWizard, Mode mode = Initial, const QString &buildDirectory = QString());
+    explicit CMakeRunPage(CMakeOpenProjectWizard *cmakeWizard, Mode mode = Initial, const QString &buildDirectory = QString());
 
     virtual void initializePage();
     virtual void cleanupPage();
diff --git a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
index d948f809abd3314ffdaa6499fb9913b40f64e380..6b46ef32d22e93ca2e9345a4651da835702fcabc 100644
--- a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
+++ b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
@@ -128,7 +128,7 @@ class CMakeRunConfigurationWidget : public QWidget
 {
     Q_OBJECT
 public:
-    CMakeRunConfigurationWidget(CMakeRunConfiguration *cmakeRunConfiguration, QWidget *parent = 0);
+    explicit CMakeRunConfigurationWidget(CMakeRunConfiguration *cmakeRunConfiguration, QWidget *parent = 0);
 
 private slots:
     void setArguments(const QString &args);
diff --git a/src/plugins/coreplugin/editormanager/editormanager.h b/src/plugins/coreplugin/editormanager/editormanager.h
index 541c5d335566975bdef14a811dcca795558e8539..0dae2ae0b954c59dfdea3e60b09e28b84aa1a481 100644
--- a/src/plugins/coreplugin/editormanager/editormanager.h
+++ b/src/plugins/coreplugin/editormanager/editormanager.h
@@ -81,7 +81,7 @@ class CORE_EXPORT EditorManagerPlaceHolder : public QWidget
 {
     Q_OBJECT
 public:
-    EditorManagerPlaceHolder(Core::IMode *mode, QWidget *parent = 0);
+    explicit EditorManagerPlaceHolder(Core::IMode *mode, QWidget *parent = 0);
     ~EditorManagerPlaceHolder();
     static EditorManagerPlaceHolder* current();
 private slots:
diff --git a/src/plugins/coreplugin/findplaceholder.h b/src/plugins/coreplugin/findplaceholder.h
index 560191630df9a7e48313009f7e4f2039a5390f85..e9dafc9da661bd9be617c8f9f5f1cd47495503d4 100644
--- a/src/plugins/coreplugin/findplaceholder.h
+++ b/src/plugins/coreplugin/findplaceholder.h
@@ -41,7 +41,7 @@ class CORE_EXPORT FindToolBarPlaceHolder : public QWidget
 {
     Q_OBJECT
 public:
-    FindToolBarPlaceHolder(QWidget *owner, QWidget *parent = 0);
+    explicit FindToolBarPlaceHolder(QWidget *owner, QWidget *parent = 0);
     ~FindToolBarPlaceHolder();
     QWidget *owner() const;
     void setWidget(QWidget *widget);
diff --git a/src/plugins/coreplugin/flowlayout.h b/src/plugins/coreplugin/flowlayout.h
index 7164909dc546f9544631301749e3ce6343d31a80..e53f5e03c14134ce5cb13539b98c1479d76a169f 100644
--- a/src/plugins/coreplugin/flowlayout.h
+++ b/src/plugins/coreplugin/flowlayout.h
@@ -38,7 +38,7 @@ namespace Internal {
 class FlowLayout : public QLayout
 {
 public:
-    FlowLayout(QWidget *parent, int margin = 0, int spacing = -1);
+    explicit FlowLayout(QWidget *parent, int margin = 0, int spacing = -1);
     FlowLayout(int spacing = -1);
     ~FlowLayout();
 
diff --git a/src/plugins/coreplugin/navigationwidget.h b/src/plugins/coreplugin/navigationwidget.h
index e609e54239240ed3e49c6abfec32364a0b522bac..e26978728649bdc55d140addfb1a6f0ac4d85e12 100644
--- a/src/plugins/coreplugin/navigationwidget.h
+++ b/src/plugins/coreplugin/navigationwidget.h
@@ -56,7 +56,7 @@ class CORE_EXPORT NavigationWidgetPlaceHolder : public QWidget
     friend class Core::NavigationWidget;
     Q_OBJECT
 public:
-    NavigationWidgetPlaceHolder(Core::IMode *mode, QWidget *parent = 0);
+    explicit NavigationWidgetPlaceHolder(Core::IMode *mode, QWidget *parent = 0);
     ~NavigationWidgetPlaceHolder();
     static NavigationWidgetPlaceHolder* current();
     void applyStoredSize(int width);
diff --git a/src/plugins/coreplugin/outputpane.h b/src/plugins/coreplugin/outputpane.h
index edfad8bb500d5d5e0643037dd44c07cb0ef40542..ba5269366197cc3d3d55c03195acee72aea4f316 100644
--- a/src/plugins/coreplugin/outputpane.h
+++ b/src/plugins/coreplugin/outputpane.h
@@ -60,7 +60,7 @@ class CORE_EXPORT OutputPanePlaceHolder : public QWidget
     friend class Core::Internal::OutputPaneManager; // needs to set m_visible and thus access m_current
     Q_OBJECT
 public:
-    OutputPanePlaceHolder(Core::IMode *mode, QSplitter *parent = 0);
+    explicit OutputPanePlaceHolder(Core::IMode *mode, QSplitter *parent = 0);
     ~OutputPanePlaceHolder();
     void setCloseable(bool b);
     bool closeable();
diff --git a/src/plugins/coreplugin/rightpane.h b/src/plugins/coreplugin/rightpane.h
index f99010e82c6f4abcaa888d1aaed65983faaa18df..e62ad881a282206da0f1792e2c5c152db2cbca2a 100644
--- a/src/plugins/coreplugin/rightpane.h
+++ b/src/plugins/coreplugin/rightpane.h
@@ -56,7 +56,7 @@ class CORE_EXPORT RightPanePlaceHolder : public QWidget
     Q_OBJECT
 
 public:
-    RightPanePlaceHolder(Core::IMode *mode, QWidget *parent = 0);
+    explicit RightPanePlaceHolder(Core::IMode *mode, QWidget *parent = 0);
     ~RightPanePlaceHolder();
     static RightPanePlaceHolder *current();
 
diff --git a/src/plugins/cppeditor/cppquickfix.h b/src/plugins/cppeditor/cppquickfix.h
index 0470cde1ed217beab54fc612454e184de7b6f30d..45cf0e86ac68e897796ecb5a7f3ccdc4fd5fa40a 100644
--- a/src/plugins/cppeditor/cppquickfix.h
+++ b/src/plugins/cppeditor/cppquickfix.h
@@ -88,7 +88,7 @@ class CPPEDITOR_EXPORT CppQuickFixOperation: public TextEditor::QuickFixOperatio
     Q_DISABLE_COPY(CppQuickFixOperation)
 
 public:
-    CppQuickFixOperation(const CppQuickFixState &state, int priority = -1);
+    explicit CppQuickFixOperation(const CppQuickFixState &state, int priority = -1);
     virtual ~CppQuickFixOperation();
 
     virtual void perform();
diff --git a/src/plugins/cvs/cvssubmiteditor.h b/src/plugins/cvs/cvssubmiteditor.h
index cd4e44b96062706c1640706c57decbf6cfc3668d..7c4db5837d1dc2905922e91230c9607175dcb078 100644
--- a/src/plugins/cvs/cvssubmiteditor.h
+++ b/src/plugins/cvs/cvssubmiteditor.h
@@ -46,8 +46,8 @@ public:
     // A list of state indicators and file names.
     typedef QPair<State, QString> StateFilePair;
 
-    CVSSubmitEditor(const VCSBase::VCSBaseSubmitEditorParameters *parameters,
-                           QWidget *parentWidget = 0);
+    explicit CVSSubmitEditor(const VCSBase::VCSBaseSubmitEditorParameters *parameters,
+                             QWidget *parentWidget = 0);
 
     void setStateList(const QList<StateFilePair> &statusOutput);
 
diff --git a/src/plugins/debugger/gdb/abstractgdbadapter.h b/src/plugins/debugger/gdb/abstractgdbadapter.h
index bdbf457484fa86772b904c3035482d7785e923d3..0f9199f84b0535b74019cfd477d4588fbbda8a3a 100644
--- a/src/plugins/debugger/gdb/abstractgdbadapter.h
+++ b/src/plugins/debugger/gdb/abstractgdbadapter.h
@@ -58,7 +58,7 @@ public:
         DumperLoadedByGdb
     };
 
-    AbstractGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit AbstractGdbAdapter(GdbEngine *engine, QObject *parent = 0);
     virtual ~AbstractGdbAdapter();
 
     virtual void write(const QByteArray &data);
diff --git a/src/plugins/debugger/gdb/abstractplaingdbadapter.h b/src/plugins/debugger/gdb/abstractplaingdbadapter.h
index 834439a4ed7beee96c6cf8423eb270a7bf0aec1e..2b9cd698f4bdf8e0c106040dc6f2b5c087750f90 100644
--- a/src/plugins/debugger/gdb/abstractplaingdbadapter.h
+++ b/src/plugins/debugger/gdb/abstractplaingdbadapter.h
@@ -41,7 +41,7 @@ class AbstractPlainGdbAdapter : public AbstractGdbAdapter
     Q_OBJECT
 
 public:
-    AbstractPlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit AbstractPlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
 
     virtual void setupInferior();
     void runEngine();
diff --git a/src/plugins/debugger/gdb/attachgdbadapter.h b/src/plugins/debugger/gdb/attachgdbadapter.h
index 8140c2d7c72014b6628184171883a777a13427a9..0803b87068ff324022c5c55f914f0cee0b03ae4c 100644
--- a/src/plugins/debugger/gdb/attachgdbadapter.h
+++ b/src/plugins/debugger/gdb/attachgdbadapter.h
@@ -48,7 +48,7 @@ class AttachGdbAdapter : public AbstractGdbAdapter
     Q_OBJECT
 
 public:
-    AttachGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit AttachGdbAdapter(GdbEngine *engine, QObject *parent = 0);
 
 private:
     DumperHandling dumperHandling() const { return DumperLoadedByGdb; }
diff --git a/src/plugins/debugger/gdb/coregdbadapter.h b/src/plugins/debugger/gdb/coregdbadapter.h
index 3b122f000e5c011db5cf33b491f6878d67b28f6e..fba322159f6dd3581217455d07ae26b1f598652f 100644
--- a/src/plugins/debugger/gdb/coregdbadapter.h
+++ b/src/plugins/debugger/gdb/coregdbadapter.h
@@ -49,7 +49,7 @@ class CoreGdbAdapter : public AbstractGdbAdapter
     Q_OBJECT
 
 public:
-    CoreGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit CoreGdbAdapter(GdbEngine *engine, QObject *parent = 0);
 
 private:
     DumperHandling dumperHandling() const { return DumperNotAvailable; }
diff --git a/src/plugins/debugger/gdb/localplaingdbadapter.h b/src/plugins/debugger/gdb/localplaingdbadapter.h
index adee27de4bbc60c0358eb919f278b4befe75ae27..5eae3d9e082b5725a4cb80951d0b570f26df1ae9 100644
--- a/src/plugins/debugger/gdb/localplaingdbadapter.h
+++ b/src/plugins/debugger/gdb/localplaingdbadapter.h
@@ -50,7 +50,7 @@ class LocalPlainGdbAdapter : public AbstractPlainGdbAdapter
     Q_OBJECT
 
 public:
-    LocalPlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit LocalPlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
 
 private:
     void startAdapter();
diff --git a/src/plugins/debugger/gdb/remoteplaingdbadapter.h b/src/plugins/debugger/gdb/remoteplaingdbadapter.h
index eb683f531c5c6abdd59cf80db28ed7e8bd62cf74..0505e3002b97da2958154c93651b1cdd3e9beb36 100644
--- a/src/plugins/debugger/gdb/remoteplaingdbadapter.h
+++ b/src/plugins/debugger/gdb/remoteplaingdbadapter.h
@@ -42,7 +42,7 @@ class DEBUGGER_EXPORT RemotePlainGdbAdapter : public AbstractPlainGdbAdapter
 
 public:
     friend class RemoteGdbProcess;
-    RemotePlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit RemotePlainGdbAdapter(GdbEngine *engine, QObject *parent = 0);
     void handleSetupDone();
     void handleSetupFailed(const QString &reason);
 
diff --git a/src/plugins/debugger/gdb/termgdbadapter.h b/src/plugins/debugger/gdb/termgdbadapter.h
index e0f483d0f9bbacc38d867c38246d25845b53a2c5..9c5a0c5eaa421c201ff0c3997927093317a061d9 100644
--- a/src/plugins/debugger/gdb/termgdbadapter.h
+++ b/src/plugins/debugger/gdb/termgdbadapter.h
@@ -50,7 +50,7 @@ class TermGdbAdapter : public AbstractGdbAdapter
     Q_OBJECT
 
 public:
-    TermGdbAdapter(GdbEngine *engine, QObject *parent = 0);
+    explicit TermGdbAdapter(GdbEngine *engine, QObject *parent = 0);
     ~TermGdbAdapter();
 
 private:
diff --git a/src/plugins/debugger/watchwindow.h b/src/plugins/debugger/watchwindow.h
index 35e294313a3537d45c17717544d96efa65032457..e3ca3bcf60440205687776fd26c3dfe812e38c89 100644
--- a/src/plugins/debugger/watchwindow.h
+++ b/src/plugins/debugger/watchwindow.h
@@ -49,7 +49,7 @@ class WatchWindow : public QTreeView
 public:
     enum Type { ReturnType, LocalsType, TooltipType, WatchersType };
 
-    WatchWindow(Type type, QWidget *parent = 0);
+    explicit WatchWindow(Type type, QWidget *parent = 0);
     Type type() const { return m_type; }
 
 public slots:
diff --git a/src/plugins/designer/qtcreatorintegration.h b/src/plugins/designer/qtcreatorintegration.h
index 7a601e1f57b1211cee01b71090a2f36c525a57fc..815a365289b25d2a4a855c83a026d39fcd20065d 100644
--- a/src/plugins/designer/qtcreatorintegration.h
+++ b/src/plugins/designer/qtcreatorintegration.h
@@ -44,7 +44,7 @@ class FormEditorW;
 class QtCreatorIntegration : public qdesigner_internal::QDesignerIntegration {
     Q_OBJECT
 public:
-    QtCreatorIntegration(QDesignerFormEditorInterface *core, FormEditorW *parent = 0);
+    explicit QtCreatorIntegration(QDesignerFormEditorInterface *core, FormEditorW *parent = 0);
 
     QWidget *containerWindow(QWidget *widget) const;
 
diff --git a/src/plugins/fakevim/fakevimhandler.h b/src/plugins/fakevim/fakevimhandler.h
index 1d2a0a8e25283b520ef9a909fb5ff79dd9c7771e..2278a416e0e41f34ec19d1e405e6259c8d24faa4 100644
--- a/src/plugins/fakevim/fakevimhandler.h
+++ b/src/plugins/fakevim/fakevimhandler.h
@@ -78,7 +78,7 @@ class FakeVimHandler : public QObject
     Q_OBJECT
 
 public:
-    FakeVimHandler(QWidget *widget, QObject *parent = 0);
+    explicit FakeVimHandler(QWidget *widget, QObject *parent = 0);
     ~FakeVimHandler();
 
     QWidget *widget();
diff --git a/src/plugins/find/searchresulttreeitems.h b/src/plugins/find/searchresulttreeitems.h
index 1c77eb9f6708bf966094f4a4739c9597b81667ca..bf4bdcddef15600f5962395c76cd1365e018bb6a 100644
--- a/src/plugins/find/searchresulttreeitems.h
+++ b/src/plugins/find/searchresulttreeitems.h
@@ -43,8 +43,8 @@ namespace Internal {
 class SearchResultTreeItem
 {
 public:
-    SearchResultTreeItem(const SearchResultItem &item = SearchResultItem(),
-                         SearchResultTreeItem *parent = NULL);
+    explicit SearchResultTreeItem(const SearchResultItem &item = SearchResultItem(),
+                                  SearchResultTreeItem *parent = NULL);
     virtual ~SearchResultTreeItem();
 
     bool isLeaf() const;
diff --git a/src/plugins/help/helpmode.h b/src/plugins/help/helpmode.h
index c856a88bb7f2b5de9001b9499ea9673a40865dd5..e74993ca311416c8bd8b815e512ae52ed5cfa658 100644
--- a/src/plugins/help/helpmode.h
+++ b/src/plugins/help/helpmode.h
@@ -42,7 +42,7 @@ class HelpMode : public Core::BaseMode
     Q_OBJECT
 
 public:
-    HelpMode(QWidget *widget, QObject *parent = 0);
+    explicit HelpMode(QWidget *widget, QObject *parent = 0);
 };
 
 } // namespace Internal
diff --git a/src/plugins/help/helpviewer.h b/src/plugins/help/helpviewer.h
index 0d1d6edee2782cbbce1e873428bbeca1f28c4ef3..43e1bfea0d6052ad2e15bd95deceda90d6c63357 100644
--- a/src/plugins/help/helpviewer.h
+++ b/src/plugins/help/helpviewer.h
@@ -60,7 +60,7 @@ class HelpViewer : public QTextBrowser
     Q_DISABLE_COPY(HelpViewer)
 
 public:
-    HelpViewer(qreal zoom, QWidget *parent = 0);
+    explicit HelpViewer(qreal zoom, QWidget *parent = 0);
     ~HelpViewer();
 
     QFont viewerFont() const;
diff --git a/src/plugins/help/openpageswidget.h b/src/plugins/help/openpageswidget.h
index 5a951ff071b468a3ea7ca6b51208d6a648aa9505..85f7949e32f0b1c26876dd4965d38398484c3588 100644
--- a/src/plugins/help/openpageswidget.h
+++ b/src/plugins/help/openpageswidget.h
@@ -56,7 +56,7 @@ class OpenPagesWidget : public QTreeView
     Q_OBJECT
 
 public:
-    OpenPagesWidget(OpenPagesModel *model, QWidget *parent = 0);
+    explicit OpenPagesWidget(OpenPagesModel *model, QWidget *parent = 0);
     ~OpenPagesWidget();
 
     void selectCurrentPage();
diff --git a/src/plugins/help/remotehelpfilter.h b/src/plugins/help/remotehelpfilter.h
index 2799ebe6c2208bfcd78224f881e8d7bc4914d5d7..e2d32fbb329fb2c2d34539c52a2d6d8791a73bdf 100644
--- a/src/plugins/help/remotehelpfilter.h
+++ b/src/plugins/help/remotehelpfilter.h
@@ -73,7 +73,7 @@ class RemoteFilterOptions : public QDialog
     friend class RemoteHelpFilter;
 
 public:
-    RemoteFilterOptions(RemoteHelpFilter *filter, QWidget *parent = 0);
+    explicit RemoteFilterOptions(RemoteHelpFilter *filter, QWidget *parent = 0);
 
 private slots:
     void addNewItem();
diff --git a/src/plugins/perforce/pendingchangesdialog.h b/src/plugins/perforce/pendingchangesdialog.h
index 4d5020f9853b8046a6fc6e89e2f22f66dc6e58f2..ae1df93d4852fdf7086c6a3064ea0f45022e451c 100644
--- a/src/plugins/perforce/pendingchangesdialog.h
+++ b/src/plugins/perforce/pendingchangesdialog.h
@@ -42,7 +42,7 @@ class PendingChangesDialog : public QDialog
     Q_OBJECT
 
 public:
-    PendingChangesDialog(const QString &data, QWidget *parent = 0);
+    explicit PendingChangesDialog(const QString &data, QWidget *parent = 0);
     int changeNumber() const;
 
 private:
diff --git a/src/plugins/projectexplorer/buildconfigurationmodel.h b/src/plugins/projectexplorer/buildconfigurationmodel.h
index 5f14552ca69ea963479ace3f235d0f8828c0f857..fb3dd785822fdf75858dadf69b613e504d6014f4 100644
--- a/src/plugins/projectexplorer/buildconfigurationmodel.h
+++ b/src/plugins/projectexplorer/buildconfigurationmodel.h
@@ -46,7 +46,7 @@ class BuildConfigurationModel : public QAbstractListModel
 {
     Q_OBJECT
 public:
-    BuildConfigurationModel(Target *target, QObject *parent = 0);
+    explicit BuildConfigurationModel(Target *target, QObject *parent = 0);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const;
     int columnCount(const QModelIndex &parent = QModelIndex()) const;
diff --git a/src/plugins/projectexplorer/deployconfigurationmodel.h b/src/plugins/projectexplorer/deployconfigurationmodel.h
index 26f553470995ec420998dfc0d92bfe0b8b7a1e6e..cb94db1624601289d5230c35745dc78cffc311e4 100644
--- a/src/plugins/projectexplorer/deployconfigurationmodel.h
+++ b/src/plugins/projectexplorer/deployconfigurationmodel.h
@@ -45,7 +45,7 @@ class DeployConfigurationModel : public QAbstractListModel
 {
     Q_OBJECT
 public:
-    DeployConfigurationModel(Target *target, QObject *parent = 0);
+    explicit DeployConfigurationModel(Target *target, QObject *parent = 0);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const;
     int columnCount(const QModelIndex &parent = QModelIndex()) const;
diff --git a/src/plugins/projectexplorer/environmenteditmodel.h b/src/plugins/projectexplorer/environmenteditmodel.h
index 489b09203e8b52212772b71995d611b0ee1e4bb4..6f15f4a9a7dad5aad4f4d6cafdb599c43c159800 100644
--- a/src/plugins/projectexplorer/environmenteditmodel.h
+++ b/src/plugins/projectexplorer/environmenteditmodel.h
@@ -96,7 +96,7 @@ class PROJECTEXPLORER_EXPORT EnvironmentWidget : public QWidget
 {
     Q_OBJECT
 public:
-    EnvironmentWidget(QWidget *parent, QWidget *additionalDetailsWidget = 0);
+    explicit EnvironmentWidget(QWidget *parent, QWidget *additionalDetailsWidget = 0);
     ~EnvironmentWidget();
 
     void setBaseEnvironmentText(const QString &text);
diff --git a/src/plugins/projectexplorer/miniprojecttargetselector.h b/src/plugins/projectexplorer/miniprojecttargetselector.h
index adaff962f7b9b22b2c421f4f2efd649c4827e6ee..551af5bbc512cdcbf6e558f9088313de7e1bfdae 100644
--- a/src/plugins/projectexplorer/miniprojecttargetselector.h
+++ b/src/plugins/projectexplorer/miniprojecttargetselector.h
@@ -57,7 +57,7 @@ private:
     ProjectExplorer::Project* m_project;
 
 public:
-    ProjectListWidget(ProjectExplorer::Project *project, QWidget *parent = 0);
+    explicit ProjectListWidget(ProjectExplorer::Project *project, QWidget *parent = 0);
 
     QSize sizeHint() const;
 
@@ -74,7 +74,7 @@ class MiniTargetWidget : public QWidget
 {
     Q_OBJECT
 public:
-    MiniTargetWidget(ProjectExplorer::Target *target, QWidget *parent = 0);
+    explicit MiniTargetWidget(ProjectExplorer::Target *target, QWidget *parent = 0);
     ProjectExplorer::Target *target() const;
 
     bool hasBuildConfiguration() const;
@@ -113,7 +113,7 @@ class MiniProjectTargetSelector : public QWidget
 {
     Q_OBJECT
 public:
-    MiniProjectTargetSelector(QAction *projectAction, QWidget *parent = 0);
+    explicit MiniProjectTargetSelector(QAction *projectAction, QWidget *parent = 0);
     void setVisible(bool visible);
 
 signals:
diff --git a/src/plugins/projectexplorer/runconfigurationmodel.h b/src/plugins/projectexplorer/runconfigurationmodel.h
index 243916769adf05d8813b4f5bafdea8261328f18d..dd311e7f482ce7c3d14fbfa59f12f279a4f8b050 100644
--- a/src/plugins/projectexplorer/runconfigurationmodel.h
+++ b/src/plugins/projectexplorer/runconfigurationmodel.h
@@ -44,7 +44,7 @@ class RunConfigurationModel : public QAbstractListModel
 {
     Q_OBJECT
 public:
-    RunConfigurationModel(Target *target, QObject *parent = 0);
+    explicit RunConfigurationModel(Target *target, QObject *parent = 0);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const;
     int columnCount(const QModelIndex &parent = QModelIndex()) const;
diff --git a/src/plugins/qmldesigner/components/itemlibrary/itemlibrarymodel.h b/src/plugins/qmldesigner/components/itemlibrary/itemlibrarymodel.h
index 5859ae61ba30266096825572929ae98c1c56a771..de29910d1bbf895ed27bfe4b12172f9005babc3c 100644
--- a/src/plugins/qmldesigner/components/itemlibrary/itemlibrarymodel.h
+++ b/src/plugins/qmldesigner/components/itemlibrary/itemlibrarymodel.h
@@ -126,7 +126,7 @@ class ItemLibraryModel: public ItemLibrarySortedModel<ItemLibrarySectionModel> {
     Q_PROPERTY(QString searchText READ searchText WRITE setSearchText NOTIFY searchTextChanged)
 
 public:
-    ItemLibraryModel(QScriptEngine *scriptEngine, QObject *parent = 0);
+    explicit ItemLibraryModel(QScriptEngine *scriptEngine, QObject *parent = 0);
     ~ItemLibraryModel();
 
     QString searchText() const;
diff --git a/src/plugins/qmldesigner/styledoutputpaneplaceholder.h b/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
index 5b788308d493bb98c0a24a77449f5f0aaacf9054..a49a2a00b8fc881efd152b289b9f99780a685517 100644
--- a/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
+++ b/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
@@ -8,7 +8,7 @@ QT_FORWARD_DECLARE_CLASS(QChildEvent)
 class StyledOutputpanePlaceHolder : public Core::OutputPanePlaceHolder
 {
 public:
-    StyledOutputpanePlaceHolder(Core::IMode *mode, QSplitter *parent = 0);
+    explicit StyledOutputpanePlaceHolder(Core::IMode *mode, QSplitter *parent = 0);
 
 protected:
     void childEvent(QChildEvent *event);
diff --git a/src/plugins/qmljseditor/qmlfilewizard.h b/src/plugins/qmljseditor/qmlfilewizard.h
index 92ec538b234df252ed1bf2d860d41e1d28eec35b..60add8bd3b093159b88cc9dbe156e2c1aa4aced9 100644
--- a/src/plugins/qmljseditor/qmlfilewizard.h
+++ b/src/plugins/qmljseditor/qmlfilewizard.h
@@ -41,8 +41,8 @@ class QmlFileWizard: public Core::StandardFileWizard
 public:
     typedef Core::BaseFileWizardParameters BaseFileWizardParameters;
 
-    QmlFileWizard(const BaseFileWizardParameters &parameters,
-                  QObject *parent = 0);
+    explicit QmlFileWizard(const BaseFileWizardParameters &parameters,
+                           QObject *parent = 0);
 
 protected:
     QString fileContents(const QString &baseName) const;
diff --git a/src/plugins/qmljseditor/qmljscodecompletion.h b/src/plugins/qmljseditor/qmljscodecompletion.h
index f435badf24dddce3aa939af05f3950301a3e789e..a2e2284c192bb129c822a76c89d16095bf777ea3 100644
--- a/src/plugins/qmljseditor/qmljscodecompletion.h
+++ b/src/plugins/qmljseditor/qmljscodecompletion.h
@@ -58,7 +58,7 @@ class CodeCompletion: public TextEditor::ICompletionCollector
     Q_OBJECT
 
 public:
-    CodeCompletion(QmlJS::ModelManagerInterface *modelManager, QObject *parent = 0);
+    explicit CodeCompletion(QmlJS::ModelManagerInterface *modelManager, QObject *parent = 0);
     virtual ~CodeCompletion();
 
     virtual TextEditor::ITextEditable *editor() const;
diff --git a/src/plugins/qmljseditor/qmljsquickfix.h b/src/plugins/qmljseditor/qmljsquickfix.h
index 50b248426b4c2088af9f931ee9fe63dee384949b..419cc73b9020124135e35ae0ff1ad4b0c602fb88 100644
--- a/src/plugins/qmljseditor/qmljsquickfix.h
+++ b/src/plugins/qmljseditor/qmljsquickfix.h
@@ -97,7 +97,7 @@ public:
         \param state The state for which this operation was created.
         \param priority The priority for this operation.
      */
-    QmlJSQuickFixOperation(const QmlJSQuickFixState &state, int priority = -1);
+    explicit QmlJSQuickFixOperation(const QmlJSQuickFixState &state, int priority = -1);
     virtual ~QmlJSQuickFixOperation();
 
     virtual void perform();
diff --git a/src/plugins/qmljseditor/qmloutlinemodel.cpp b/src/plugins/qmljseditor/qmloutlinemodel.cpp
index 8d9186c27edb676bc7e5b9d40bb4878c34ad4594..23e42770cda76485b379f3f88fd9693963284906 100644
--- a/src/plugins/qmljseditor/qmloutlinemodel.cpp
+++ b/src/plugins/qmljseditor/qmloutlinemodel.cpp
@@ -493,8 +493,8 @@ AST::Node *QmlOutlineModel::nodeForIndex(const QModelIndex &index) const
 
 AST::SourceLocation QmlOutlineModel::sourceLocation(const QModelIndex &index) const
 {
-    QTC_ASSERT(index.isValid() && (index.model() == this), return 0);
     AST::SourceLocation location;
+    QTC_ASSERT(index.isValid() && (index.model() == this), return location);
     AST::Node *node = nodeForIndex(index);
     if (node) {
         if (AST::UiObjectMember *member = node->uiObjectMemberCast())
diff --git a/src/plugins/qmljsinspector/qmljsdesigndebugclient.h b/src/plugins/qmljsinspector/qmljsdesigndebugclient.h
index 40c1654a44a9062d9a7d15ec9cc40605a8bd3b95..da252aff6c2f2122262a095c82739ba0780bbf22 100644
--- a/src/plugins/qmljsinspector/qmljsdesigndebugclient.h
+++ b/src/plugins/qmljsinspector/qmljsdesigndebugclient.h
@@ -51,8 +51,8 @@ class QmlJSDesignDebugClient : public QDeclarativeDebugClient
 {
     Q_OBJECT
 public:
-    QmlJSDesignDebugClient(QDeclarativeDebugConnection *client,
-                                  QObject *parent = 0);
+    explicit QmlJSDesignDebugClient(QDeclarativeDebugConnection *client,
+                                    QObject *parent = 0);
 
     void setSelectedItemsByObjectId(const QList<QDeclarativeDebugObjectReference> &objects);
     void reloadViewer();
diff --git a/src/plugins/qt4projectmanager/projectloadwizard.h b/src/plugins/qt4projectmanager/projectloadwizard.h
index b6e56d6ce1353910e30270b5010bcbe650845d9b..8d4711db89c4df93cda5f06267b9080dcb54b8d7 100644
--- a/src/plugins/qt4projectmanager/projectloadwizard.h
+++ b/src/plugins/qt4projectmanager/projectloadwizard.h
@@ -42,7 +42,7 @@ class ProjectLoadWizard : public QWizard
 {
     Q_OBJECT
 public:
-    ProjectLoadWizard(Qt4Project *project, QWidget * parent = 0, Qt::WindowFlags flags = 0);
+    explicit ProjectLoadWizard(Qt4Project *project, QWidget * parent = 0, Qt::WindowFlags flags = 0);
     virtual ~ProjectLoadWizard();
     virtual void done(int result);
     void execDialog();
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60devicespreferencepane.h b/src/plugins/qt4projectmanager/qt-s60/s60devicespreferencepane.h
index a48ae3995109c556fade63badffc63ec0c54fc60..ee4b65f89a1650f660c8e62cb2afae1c0172ee8d 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60devicespreferencepane.h
+++ b/src/plugins/qt4projectmanager/qt-s60/s60devicespreferencepane.h
@@ -124,7 +124,7 @@ class S60DevicesPreferencePane : public Core::IOptionsPage
 {
     Q_OBJECT
 public:
-    S60DevicesPreferencePane(S60Devices *devices, QObject *parent = 0);
+    explicit S60DevicesPreferencePane(S60Devices *devices, QObject *parent = 0);
     ~S60DevicesPreferencePane();
 
     QString id() const;
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.h b/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.h
index 39d1911d84153e935da7f9d5d119ac1614ae46ea..1f272a2cc59c143f00f3577ea99370eb0038d652 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.h
+++ b/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.h
@@ -94,8 +94,8 @@ class S60EmulatorRunConfigurationWidget : public QWidget
 {
     Q_OBJECT
 public:
-    S60EmulatorRunConfigurationWidget(S60EmulatorRunConfiguration *runConfiguration,
-                                      QWidget *parent = 0);
+    explicit S60EmulatorRunConfigurationWidget(S60EmulatorRunConfiguration *runConfiguration,
+                                               QWidget *parent = 0);
 
 private slots:
     void updateTargetInformation();
diff --git a/src/plugins/qt4projectmanager/qtversionmanager.h b/src/plugins/qt4projectmanager/qtversionmanager.h
index d88538a5bc57a90035b5079bb9ccdf5cdc432b9f..2352119767422ea434f1dd84f1473ae8a2eabcf0 100644
--- a/src/plugins/qt4projectmanager/qtversionmanager.h
+++ b/src/plugins/qt4projectmanager/qtversionmanager.h
@@ -53,7 +53,7 @@ public:
     QtVersion(const QString &name, const QString &qmakeCommand,
               bool isAutodetected = false, const QString &autodetectionSource = QString());
 
-    QtVersion(const QString &path, bool isAutodetected = false, const QString &autodetectionSource = QString());
+    explicit QtVersion(const QString &path, bool isAutodetected = false, const QString &autodetectionSource = QString());
 
     QtVersion(const QString &name, const QString &qmakeCommand, int id,
               bool isAutodetected = false, const QString &autodetectionSource = QString());
diff --git a/src/plugins/subversion/subversionsubmiteditor.h b/src/plugins/subversion/subversionsubmiteditor.h
index 192eb1fae984a99288a932838b869cbe255c3437..f9951748726db01ee1b0da935a964ce10c1bde74 100644
--- a/src/plugins/subversion/subversionsubmiteditor.h
+++ b/src/plugins/subversion/subversionsubmiteditor.h
@@ -42,8 +42,8 @@ class SubversionSubmitEditor : public VCSBase::VCSBaseSubmitEditor
 {
     Q_OBJECT
 public:
-    SubversionSubmitEditor(const VCSBase::VCSBaseSubmitEditorParameters *parameters,
-                           QWidget *parentWidget = 0);
+    explicit SubversionSubmitEditor(const VCSBase::VCSBaseSubmitEditorParameters *parameters,
+                                    QWidget *parentWidget = 0);
 
     static QString fileFromStatusLine(const QString &statusLine);
 
diff --git a/src/plugins/texteditor/texteditoractionhandler.h b/src/plugins/texteditor/texteditoractionhandler.h
index 93bbb0611e35c6dd6cd50565514418a97680fd64..cfa7f019d7e6c772f48b4baaee67e4d0d2001d3e 100644
--- a/src/plugins/texteditor/texteditoractionhandler.h
+++ b/src/plugins/texteditor/texteditoractionhandler.h
@@ -57,7 +57,7 @@ public:
         UnCollapseAll = 4
     };
 
-    TextEditorActionHandler(const char *context, uint optionalActions = None);
+    explicit TextEditorActionHandler(const char *context, uint optionalActions = None);
     void setupActions(BaseTextEditor *editor);
 
     void initializeActions();
diff --git a/src/plugins/vcsbase/checkoutwizarddialog.h b/src/plugins/vcsbase/checkoutwizarddialog.h
index 97d029f6ffc18657d77b726529734a77d5413674..4fea4241eba1e13262ae7ece6296105f46757cde 100644
--- a/src/plugins/vcsbase/checkoutwizarddialog.h
+++ b/src/plugins/vcsbase/checkoutwizarddialog.h
@@ -47,8 +47,8 @@ class CheckoutProgressWizardPage;
 class CheckoutWizardDialog : public Utils::Wizard {
     Q_OBJECT
 public:
-    CheckoutWizardDialog(const QList<QWizardPage *> &parameterPages,
-                         QWidget *parent = 0);
+    explicit CheckoutWizardDialog(const QList<QWizardPage *> &parameterPages,
+                                  QWidget *parent = 0);
 
     void start(const QSharedPointer<AbstractCheckoutJob> &job);
 
diff --git a/src/shared/help/bookmarkmanager.h b/src/shared/help/bookmarkmanager.h
index 788f83eb9c0be9f8e5a93f980b83db4d87e3d7fc..456ede349dcd765083a7ddf76c6248aa269d6dc9 100644
--- a/src/shared/help/bookmarkmanager.h
+++ b/src/shared/help/bookmarkmanager.h
@@ -109,8 +109,8 @@ class BookmarkWidget : public QWidget
     Q_OBJECT
 
 public:
-    BookmarkWidget(BookmarkManager *manager, QWidget *parent = 0,
-        bool showButtons = true);
+    explicit BookmarkWidget(BookmarkManager *manager, QWidget *parent = 0,
+                            bool showButtons = true);
     ~BookmarkWidget();
 
 signals:
diff --git a/src/shared/qrceditor/resourcefile_p.h b/src/shared/qrceditor/resourcefile_p.h
index d5f20f73c848fe4cbc4cd998561f477e7b6c74b9..780a7652489df99df84296299d83d5a21b7249b2 100644
--- a/src/shared/qrceditor/resourcefile_p.h
+++ b/src/shared/qrceditor/resourcefile_p.h
@@ -192,7 +192,7 @@ class ResourceModel : public QAbstractItemModel
     Q_OBJECT
 
 public:
-    ResourceModel(const ResourceFile &resource_file, QObject *parent = 0);
+    explicit ResourceModel(const ResourceFile &resource_file, QObject *parent = 0);
 
     QModelIndex index(int row, int column,
                         const QModelIndex &parent = QModelIndex()) const;
diff --git a/src/shared/qrceditor/resourceview.h b/src/shared/qrceditor/resourceview.h
index 2e44da25a7f0d0268d1bccf088d707076a25d89d..981382ff6b111b299bef7c4783e0c1946668ee1f 100644
--- a/src/shared/qrceditor/resourceview.h
+++ b/src/shared/qrceditor/resourceview.h
@@ -83,7 +83,7 @@ public:
         LanguageProperty
     };
 
-    ResourceView(QUndoStack *history, QWidget *parent = 0);
+    explicit ResourceView(QUndoStack *history, QWidget *parent = 0);
     ~ResourceView();
 
     bool load(const QString &fileName);
diff --git a/src/shared/qtsingleapplication/qtlocalpeer.h b/src/shared/qtsingleapplication/qtlocalpeer.h
index 630f0035dca7b75cdb4d7f67e3f3b9e54ad01ba6..b9f3f45c1ef150c3650f4a189c8e6fac1559fcf7 100644
--- a/src/shared/qtsingleapplication/qtlocalpeer.h
+++ b/src/shared/qtsingleapplication/qtlocalpeer.h
@@ -40,7 +40,7 @@ class QtLocalPeer : public QObject
     Q_OBJECT
 
 public:
-    QtLocalPeer(QObject *parent = 0, const QString &appId = QString());
+    explicit QtLocalPeer(QObject *parent = 0, const QString &appId = QString());
     bool isClient();
     bool sendMessage(const QString &message, int timeout);
     QString applicationId() const
diff --git a/src/shared/qtsingleapplication/qtsingleapplication.h b/src/shared/qtsingleapplication/qtsingleapplication.h
index 1ebd68fb11d607ada6b1880e4c303f34eeb93386..8a336272becf1916a7477a295aafdff282b5291d 100644
--- a/src/shared/qtsingleapplication/qtsingleapplication.h
+++ b/src/shared/qtsingleapplication/qtsingleapplication.h
@@ -42,7 +42,7 @@ public:
     QtSingleApplication(const QString &id, int &argc, char **argv);
     QtSingleApplication(int &argc, char **argv, Type type);
 #if defined(Q_WS_X11)
-    QtSingleApplication(Display *dpy, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
+    explicit QtSingleApplication(Display *dpy, Qt::HANDLE visual = 0, Qt::HANDLE colormap = 0);
     QtSingleApplication(Display *dpy, int &argc, char **argv, Qt::HANDLE visual = 0, Qt::HANDLE cmap = 0);
 #endif
 
diff --git a/src/tools/qml/qmlobserver/qmlruntime.h b/src/tools/qml/qmlobserver/qmlruntime.h
index e330fa1185ad70e0c73b016da90c59b16beb1e35..47491e67125757352fbfd0231bea8c1eced1a147 100644
--- a/src/tools/qml/qmlobserver/qmlruntime.h
+++ b/src/tools/qml/qmlobserver/qmlruntime.h
@@ -78,7 +78,7 @@ class QDeclarativeViewer
     Q_OBJECT
 
 public:
-    QDeclarativeViewer(QWidget *parent = 0, Qt::WindowFlags flags = 0);
+    explicit QDeclarativeViewer(QWidget *parent = 0, Qt::WindowFlags flags = 0);
     ~QDeclarativeViewer();
 
     static void registerTypes();