diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
index 4e566a780..8277645e7 100644
--- a/gui/mainwindow.cpp
+++ b/gui/mainwindow.cpp
@@ -1410,7 +1410,7 @@ void MainWindow::analyzeProject(const ProjectFile *projectFile)
 
 void MainWindow::newProjectFile()
 {
-    const QString filter = tr("Project files (*.cppcheck);;All files(*.*)");
+    const QString filter = tr("Project files (*.cppcheck)");
     QString filepath = QFileDialog::getSaveFileName(this,
                        tr("Select Project Filename"),
                        getPath(SETTINGS_LAST_PROJECT_PATH),
@@ -1418,6 +1418,8 @@ void MainWindow::newProjectFile()
 
     if (filepath.isEmpty())
         return;
+    if (!filepath.endsWith(".cppcheck", Qt::CaseInsensitive))
+        filepath += ".cppcheck";
 
     setPath(SETTINGS_LAST_PROJECT_PATH, filepath);
 
@@ -1427,12 +1429,10 @@ void MainWindow::newProjectFile()
 
     delete mProjectFile;
     mProjectFile = new ProjectFile(this);
+    mProjectFile->setFilename(filepath);
 
-    ProjectFileDialog dlg(filepath, this);
-    dlg.loadFromProjectFile(mProjectFile);
+    ProjectFileDialog dlg(mProjectFile, this);
     if (dlg.exec() == QDialog::Accepted) {
-        dlg.saveToProjectFile(mProjectFile);
-        mProjectFile->write();
         addProjectMRU(filepath);
         analyzeProject(mProjectFile);
     } else {
@@ -1461,10 +1461,8 @@ void MainWindow::editProjectFile()
         return;
     }
 
-    ProjectFileDialog dlg(mProjectFile->getFilename(), this);
-    dlg.loadFromProjectFile(mProjectFile);
+    ProjectFileDialog dlg(mProjectFile, this);
     if (dlg.exec() == QDialog::Accepted) {
-        dlg.saveToProjectFile(mProjectFile);
         mProjectFile->write();
         analyzeProject(mProjectFile);
     }
diff --git a/gui/projectfiledialog.cpp b/gui/projectfiledialog.cpp
index 4264106d3..70d1968b0 100644
--- a/gui/projectfiledialog.cpp
+++ b/gui/projectfiledialog.cpp
@@ -32,13 +32,13 @@
 #include "cppcheck.h"
 #include "errorlogger.h"
 
-ProjectFileDialog::ProjectFileDialog(const QString &path, QWidget *parent)
+ProjectFileDialog::ProjectFileDialog(ProjectFile *projectFile, QWidget *parent)
     : QDialog(parent)
-    , mFilePath(path)
+    , mProjectFile(projectFile)
 {
     mUI.setupUi(this);
 
-    const QFileInfo inf(path);
+    const QFileInfo inf(projectFile->getFilename());
     QString filename = inf.fileName();
     QString title = tr("Project file: %1").arg(filename);
     setWindowTitle(title);
@@ -90,7 +90,7 @@ ProjectFileDialog::ProjectFileDialog(const QString &path, QWidget *parent)
         mLibraryCheckboxes << checkbox;
     }
 
-    connect(mUI.mButtons, &QDialogButtonBox::accepted, this, &ProjectFileDialog::accept);
+    connect(mUI.mButtons, &QDialogButtonBox::accepted, this, &ProjectFileDialog::ok);
     connect(mUI.mBtnBrowseBuildDir, &QPushButton::clicked, this, &ProjectFileDialog::browseBuildDir);
     connect(mUI.mBtnClearImportProject, &QPushButton::clicked, this, &ProjectFileDialog::clearImportProject);
     connect(mUI.mBtnBrowseImportProject, &QPushButton::clicked, this, &ProjectFileDialog::browseImportProject);
@@ -107,6 +107,8 @@ ProjectFileDialog::ProjectFileDialog(const QString &path, QWidget *parent)
     connect(mUI.mBtnIncludeDown, &QPushButton::clicked, this, &ProjectFileDialog::moveIncludePathDown);
     connect(mUI.mBtnAddSuppression, &QPushButton::clicked, this, &ProjectFileDialog::addSuppression);
     connect(mUI.mBtnRemoveSuppression, &QPushButton::clicked, this, &ProjectFileDialog::removeSuppression);
+
+    loadFromProjectFile(projectFile);
 }
 
 ProjectFileDialog::~ProjectFileDialog()
@@ -155,9 +157,16 @@ void ProjectFileDialog::saveToProjectFile(ProjectFile *projectFile) const
     projectFile->setSuppressions(getSuppressions());
 }
 
+void ProjectFileDialog::ok()
+{
+    saveToProjectFile(mProjectFile);
+    mProjectFile->write();
+    accept();
+}
+
 QString ProjectFileDialog::getExistingDirectory(const QString &caption, bool trailingSlash)
 {
-    const QFileInfo inf(mFilePath);
+    const QFileInfo inf(mProjectFile->getFilename());
     const QString rootpath = inf.absolutePath();
     QString selectedDir = QFileDialog::getExistingDirectory(this,
                           caption,
@@ -211,7 +220,7 @@ void ProjectFileDialog::clearImportProject()
 
 void ProjectFileDialog::browseImportProject()
 {
-    const QFileInfo inf(mFilePath);
+    const QFileInfo inf(mProjectFile->getFilename());
     const QDir &dir = inf.absoluteDir();
     QString fileName = QFileDialog::getOpenFileName(this, tr("Import Project"),
                        dir.canonicalPath(),
diff --git a/gui/projectfiledialog.h b/gui/projectfiledialog.h
index 2e27730b2..824aaff3e 100644
--- a/gui/projectfiledialog.h
+++ b/gui/projectfiledialog.h
@@ -40,13 +40,13 @@ class ProjectFile;
 class ProjectFileDialog : public QDialog {
     Q_OBJECT
 public:
-    ProjectFileDialog(const QString &path, QWidget *parent = 0);
+    ProjectFileDialog(ProjectFile *projectFile, QWidget *parent = 0);
     virtual ~ProjectFileDialog();
 
+private:
     void loadFromProjectFile(const ProjectFile *projectFile);
     void saveToProjectFile(ProjectFile *projectFile) const;
 
-private:
     /** Enable and disable widgets in the 'Paths and Defines' tab */
     void updatePathsAndDefines();
 
@@ -146,6 +146,9 @@ private:
 
 protected slots:
 
+    /** ok button pressed, save changes and accept */
+    void ok();
+
     /**
     * @brief Browse for build dir.
     */
@@ -263,7 +266,7 @@ private:
     /**
      * @brief Projectfile path.
      */
-    QString mFilePath;
+    ProjectFile *mProjectFile;
 
     /** @brief Library checkboxes */
     QList<QCheckBox*> mLibraryCheckboxes;