diff --git a/src/plugins/nextcloud/nextcloudjob.h b/src/plugins/nextcloud/nextcloudjob.h
--- a/src/plugins/nextcloud/nextcloudjob.h
+++ b/src/plugins/nextcloud/nextcloudjob.h
@@ -3,15 +3,15 @@
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either 
+ License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
- You should have received a copy of the GNU Lesser General Public 
+ You should have received a copy of the GNU Lesser General Public
  License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
 
@@ -26,7 +26,7 @@
 {
     Q_OBJECT
     public:
-        NextcloudJob(QObject* parent)
+        explicit NextcloudJob(QObject* parent)
             : Purpose::Job(parent), m_pendingJobs(0)
         {}
         void start() override;
diff --git a/src/plugins/phabricator/phabricatorjobs.h b/src/plugins/phabricator/phabricatorjobs.h
--- a/src/plugins/phabricator/phabricatorjobs.h
+++ b/src/plugins/phabricator/phabricatorjobs.h
@@ -116,7 +116,7 @@
             enum Status { Accepted, NeedsReview, NeedsRevision };
             Q_ENUM(Status)
 
-            DiffRevList(const QString& projectDir, QObject* parent = nullptr);
+            explicit DiffRevList(const QString& projectDir, QObject* parent = nullptr);
             // return the open diff. revisions as a list of <diffID,diffDescription> pairs
             QList<QPair<QString,QString> > reviews() const
             {
diff --git a/src/plugins/phabricator/quick/difflistmodel.h b/src/plugins/phabricator/quick/difflistmodel.h
--- a/src/plugins/phabricator/quick/difflistmodel.h
+++ b/src/plugins/phabricator/quick/difflistmodel.h
@@ -32,7 +32,7 @@
     Q_OBJECT
     Q_PROPERTY(QString status READ status WRITE setStatus)
     public:
-        DiffListModel(QObject* parent = nullptr);
+        explicit DiffListModel(QObject* parent = nullptr);
 
         void refresh();
 
diff --git a/src/plugins/phabricator/quick/phabricatorrc.h b/src/plugins/phabricator/quick/phabricatorrc.h
--- a/src/plugins/phabricator/quick/phabricatorrc.h
+++ b/src/plugins/phabricator/quick/phabricatorrc.h
@@ -28,7 +28,7 @@
     Q_OBJECT
     Q_PROPERTY(QUrl path READ path WRITE setPath NOTIFY dataChanged)
     public:
-        PhabricatorRC(QObject* parent = nullptr);
+        explicit PhabricatorRC(QObject* parent = nullptr);
 
         void setPath(const QUrl &path);
 
diff --git a/src/plugins/reviewboard/quick/rbrepositoriesmodel.h b/src/plugins/reviewboard/quick/rbrepositoriesmodel.h
--- a/src/plugins/reviewboard/quick/rbrepositoriesmodel.h
+++ b/src/plugins/reviewboard/quick/rbrepositoriesmodel.h
@@ -29,7 +29,7 @@
 Q_OBJECT
 Q_PROPERTY(QUrl server READ server WRITE setServer)
 public:
-    RepositoriesModel(QObject* parent = nullptr);
+    explicit RepositoriesModel(QObject* parent = nullptr);
 
     int rowCount(const QModelIndex & parent) const override;
     QVariant data(const QModelIndex & index, int role) const override;
diff --git a/src/plugins/reviewboard/quick/rbreviewslistmodel.h b/src/plugins/reviewboard/quick/rbreviewslistmodel.h
--- a/src/plugins/reviewboard/quick/rbreviewslistmodel.h
+++ b/src/plugins/reviewboard/quick/rbreviewslistmodel.h
@@ -34,7 +34,7 @@
     Q_PROPERTY(QString status READ status WRITE setStatus)
     Q_PROPERTY(QString repository READ repository WRITE setRepository)
     public:
-        ReviewsListModel(QObject* parent = nullptr);
+        explicit ReviewsListModel(QObject* parent = nullptr);
 
         void refresh();
 
diff --git a/src/plugins/reviewboard/quick/reviewboardrc.h b/src/plugins/reviewboard/quick/reviewboardrc.h
--- a/src/plugins/reviewboard/quick/reviewboardrc.h
+++ b/src/plugins/reviewboard/quick/reviewboardrc.h
@@ -32,7 +32,7 @@
     Q_PROPERTY(QString repository READ repository NOTIFY dataChanged)
     Q_PROPERTY(QJsonObject extraData READ extraData NOTIFY dataChanged)
     public:
-        ReviewboardRC(QObject* parent = nullptr);
+        explicit ReviewboardRC(QObject* parent = nullptr);
 
         void setPath(const QUrl &path);
 
diff --git a/src/plugins/reviewboard/reviewboardjobs.h b/src/plugins/reviewboard/reviewboardjobs.h
--- a/src/plugins/reviewboard/reviewboardjobs.h
+++ b/src/plugins/reviewboard/reviewboardjobs.h
@@ -133,7 +133,7 @@
     {
         Q_OBJECT
         public:
-            ProjectsListRequest(const QUrl &server, QObject* parent = nullptr);
+            explicit ProjectsListRequest(const QUrl &server, QObject* parent = nullptr);
             void start() override;
             QVariantList repositories() const;