diff --git a/gui/checkthread.cpp b/gui/checkthread.cpp
index 671e068ae..2592567d4 100644
--- a/gui/checkthread.cpp
+++ b/gui/checkthread.cpp
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <QApplication>
 #include <QString>
 #include <QDebug>
 #include <QDir>
@@ -74,13 +75,11 @@ void CheckThread::run()
         return;
     }
 
-    const QString addonPath = getAddonPath();
-
     QString file = mResult.getNextFile();
     while (!file.isEmpty() && mState == Running) {
         qDebug() << "Checking file" << file;
         mCppcheck.check(file.toStdString());
-        runAddonsAndTools(addonPath, nullptr, file);
+        runAddonsAndTools(nullptr, file);
         emit fileChecked(file);
 
         if (mState == Running)
@@ -92,7 +91,7 @@ void CheckThread::run()
         file = QString::fromStdString(fileSettings.filename);
         qDebug() << "Checking file" << file;
         mCppcheck.check(fileSettings);
-        runAddonsAndTools(addonPath, &fileSettings, QString::fromStdString(fileSettings.filename));
+        runAddonsAndTools(&fileSettings, QString::fromStdString(fileSettings.filename));
         emit fileChecked(file);
 
         if (mState == Running)
@@ -107,7 +106,7 @@ void CheckThread::run()
     emit done();
 }
 
-void CheckThread::runAddonsAndTools(const QString &addonPath, const ImportProject::FileSettings *fileSettings, const QString &fileName)
+void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSettings, const QString &fileName)
 {
     QString dumpFile;
 
@@ -263,13 +262,12 @@ void CheckThread::runAddonsAndTools(const QString &addonPath, const ImportProjec
 
             parseClangErrors(addon, fileName, errout);
         } else {
-            QString a;
-            if (QFileInfo(addonPath + '/' + addon + ".py").exists())
-                a = addonPath + '/' + addon + ".py";
-            else if (QFileInfo(addonPath + '/' + addon + '/' + addon + ".py").exists())
-                a = addonPath + '/' + addon + '/' + addon + ".py";
-            else
-                continue;
+            QString a = CheckThread::getAddonFilePath(mDataDir, addon + ".py");
+            if (a.isEmpty()) {
+                a = CheckThread::getAddonFilePath(QApplication::applicationDirPath(), addon + ".py");
+                if (a.isEmpty())
+                    continue;
+            }
 
             if (dumpFile.isEmpty()) {
                 const std::string buildDir = mCppcheck.settings().buildDir;
@@ -321,21 +319,6 @@ void CheckThread::stop()
     mCppcheck.terminate();
 }
 
-QString CheckThread::getAddonPath() const
-{
-    if (QFileInfo(mDataDir + "/threadsafety.py").exists())
-        return mDataDir;
-    else if (QDir(mDataDir + "/addons").exists())
-        return mDataDir + "/addons";
-    else if (QDir(mDataDir + "/../addons").exists())
-        return mDataDir + "/../addons";
-    else if (mDataDir.endsWith("/cfg")) {
-        if (QDir(mDataDir.mid(0,mDataDir.size()-3) + "addons").exists())
-            return mDataDir.mid(0,mDataDir.size()-3) + "addons";
-    }
-    return QString();
-}
-
 void CheckThread::parseAddonErrors(QString err, QString tool)
 {
     Q_UNUSED(tool);
@@ -447,3 +430,16 @@ void CheckThread::parseClangErrors(const QString &tool, const QString &file0, QS
         mResult.reportErr(errmsg);
     }
 }
+
+QString CheckThread::getAddonFilePath(const QString &dataDir, const QString &addonFile)
+{
+    if (dataDir.isEmpty())
+        return QString();
+    if (QFileInfo(dataDir + '/' + addonFile).exists())
+        return dataDir + '/' + addonFile;
+    if (QFileInfo(dataDir + "/addons/" + addonFile).exists())
+        return dataDir + "/addons/" + addonFile;
+    if (QFileInfo(dataDir + "/../addons/" + addonFile).exists())
+        return dataDir + "/../addons/" + addonFile;
+    return QString();
+}
diff --git a/gui/checkthread.h b/gui/checkthread.h
index 5605e4fa8..b01dac7c9 100644
--- a/gui/checkthread.h
+++ b/gui/checkthread.h
@@ -84,6 +84,7 @@ public:
 
     void stop();
 
+    static QString getAddonFilePath(const QString &dataDir, const QString &addonFile);
 
 signals:
 
@@ -122,9 +123,7 @@ protected:
     CppCheck mCppcheck;
 
 private:
-    QString getAddonPath() const;
-
-    void runAddonsAndTools(const QString &addonPath, const ImportProject::FileSettings *fileSettings, const QString &fileName);
+    void runAddonsAndTools(const ImportProject::FileSettings *fileSettings, const QString &fileName);
 
     void parseAddonErrors(QString err, QString tool);
     void parseClangErrors(const QString &tool, const QString &file0, QString err);
diff --git a/gui/projectfiledialog.cpp b/gui/projectfiledialog.cpp
index 3984ff2d7..b9fd277eb 100644
--- a/gui/projectfiledialog.cpp
+++ b/gui/projectfiledialog.cpp
@@ -28,6 +28,7 @@
 #include <QProcess>
 #include "common.h"
 #include "projectfiledialog.h"
+#include "checkthread.h"
 #include "projectfile.h"
 #include "library.h"
 #include "cppcheck.h"
@@ -160,6 +161,16 @@ void ProjectFileDialog::saveSettings() const
     settings.setValue(SETTINGS_PROJECT_DIALOG_HEIGHT, size().height());
 }
 
+static void updateAddonCheckBox(QCheckBox *cb, const ProjectFile *projectFile, const QString &dataDir, const QString &addon)
+{
+    cb->setChecked(projectFile->getAddons().contains(addon));
+    const QString appPath = QApplication::applicationDirPath();
+    if (CheckThread::getAddonFilePath(dataDir, addon + ".py").isEmpty() && CheckThread::getAddonFilePath(appPath, addon + ".py").isEmpty()) {
+        cb->setEnabled(false);
+        cb->setText(cb->text() + QObject::tr(" (Not found)"));
+    }
+}
+
 void ProjectFileDialog::loadFromProjectFile(const ProjectFile *projectFile)
 {
     setRootPath(projectFile->getRootPath());
@@ -172,7 +183,13 @@ void ProjectFileDialog::loadFromProjectFile(const ProjectFile *projectFile)
     setExcludedPaths(projectFile->getExcludedPaths());
     setLibraries(projectFile->getLibraries());
     setSuppressions(projectFile->getSuppressions());
-    mUI.mAddonThreadSafety->setChecked(projectFile->getAddons().contains("threadsafety"));
+
+    QSettings settings;
+    const QString dataDir = settings.value("DATADIR", QString()).toString();
+    updateAddonCheckBox(mUI.mAddonThreadSafety, projectFile, dataDir, "threadsafety");
+    updateAddonCheckBox(mUI.mAddonY2038, projectFile, dataDir, "y2038");
+    updateAddonCheckBox(mUI.mAddonCert, projectFile, dataDir, "cert");
+
     mUI.mAddonY2038->setChecked(projectFile->getAddons().contains("y2038"));
     mUI.mAddonCert->setChecked(projectFile->getAddons().contains("cert"));
     mUI.mToolClangAnalyzer->setChecked(projectFile->getClangAnalyzer());