diff --git a/gui/applicationlist.cpp b/gui/applicationlist.cpp
index 599175145..ab1285337 100644
--- a/gui/applicationlist.cpp
+++ b/gui/applicationlist.cpp
@@ -21,8 +21,6 @@
 #include "application.h"
 #include "common.h"
 
-#include <cstdlib>
-
 #include <QFileInfo>
 #include <QSettings>
 #include <QStringList>
diff --git a/gui/main.cpp b/gui/main.cpp
index b57eb7d6f..7a79be5b7 100644
--- a/gui/main.cpp
+++ b/gui/main.cpp
@@ -32,7 +32,6 @@
 
 #include <QApplication>
 #include <QCoreApplication>
-#include <QMetaType>
 #include <QStringList>
 #include <QSettings>
 
diff --git a/gui/showtypes.cpp b/gui/showtypes.cpp
index 0c636ebee..24ebbb962 100644
--- a/gui/showtypes.cpp
+++ b/gui/showtypes.cpp
@@ -20,9 +20,7 @@
 
 #include "common.h"
 
-#include <QMap>
 #include <QSettings>
-#include <QString>
 
 ShowTypes::ShowTypes()
 {
diff --git a/gui/statsdialog.cpp b/gui/statsdialog.cpp
index 525c9c96d..67b1215f9 100644
--- a/gui/statsdialog.cpp
+++ b/gui/statsdialog.cpp
@@ -31,6 +31,17 @@
 #include <QTextDocument>
 #include <QWidget>
 
+#ifdef HAVE_QCHART
+#include <QAbstractSeries>
+#include <QChartView>
+#include <QDateTimeAxis>
+#include <QLineSeries>
+#include <QTextStream>
+#include <QValueAxis>
+
+using namespace QtCharts;
+#endif
+
 static const QString CPPCHECK("cppcheck");
 
 StatsDialog::StatsDialog(QWidget *parent)
diff --git a/gui/statsdialog.h b/gui/statsdialog.h
index 66516cd7b..c8190d82a 100644
--- a/gui/statsdialog.h
+++ b/gui/statsdialog.h
@@ -22,13 +22,17 @@
 #include "ui_stats.h"
 
 #include <QDialog>
-#ifdef HAVE_QCHART
-#include <QtCharts>
-#endif
 
 class ProjectFile;
 class CheckStatistics;
 
+#ifdef HAVE_QCHART
+namespace QtCharts {
+    class QChartView;
+    class QLineSeries;
+}
+#endif
+
 /// @addtogroup GUI
 /// @{
 
@@ -70,8 +74,8 @@ private slots:
     void copyToClipboard();
     void pdfExport();
 #ifdef HAVE_QCHART
-    QChartView *createChart(const QString &statsFile, const QString &tool);
-    QLineSeries *numberOfReports(const QString &fileName, const QString &severity) const;
+    QtCharts::QChartView *createChart(const QString &statsFile, const QString &tool);
+    QtCharts::QLineSeries *numberOfReports(const QString &fileName, const QString &severity) const;
 #endif
 private:
     Ui::StatsDialog mUI;
diff --git a/gui/test/benchmark/simple/benchmarksimple.cpp b/gui/test/benchmark/simple/benchmarksimple.cpp
index 139afecb9..2968b1e13 100644
--- a/gui/test/benchmark/simple/benchmarksimple.cpp
+++ b/gui/test/benchmark/simple/benchmarksimple.cpp
@@ -19,15 +19,14 @@
 #include "benchmarksimple.h"
 
 #include "settings.h"
-#include "token.h"
 #include "tokenize.h"
 
 #include <sstream>
 
 #include <QByteArray>
 #include <QFile>
-#include <QObject>
 #include <QString>
+#include <QtTest>
 
 void BenchmarkSimple::tokenize()
 {
diff --git a/gui/test/benchmark/simple/benchmarksimple.h b/gui/test/benchmark/simple/benchmarksimple.h
index 1f021700f..ec5ca9974 100644
--- a/gui/test/benchmark/simple/benchmarksimple.h
+++ b/gui/test/benchmark/simple/benchmarksimple.h
@@ -19,7 +19,6 @@
 #include "errorlogger.h"
 
 #include <QObject>
-#include <QtTest/QtTest>
 
 class BenchmarkSimple : public QObject, public ErrorLogger {
     Q_OBJECT
diff --git a/gui/test/cppchecklibrarydata/testcppchecklibrarydata.cpp b/gui/test/cppchecklibrarydata/testcppchecklibrarydata.cpp
index 71659b7cf..3088b007b 100644
--- a/gui/test/cppchecklibrarydata/testcppchecklibrarydata.cpp
+++ b/gui/test/cppchecklibrarydata/testcppchecklibrarydata.cpp
@@ -18,6 +18,9 @@
 
 #include "testcppchecklibrarydata.h"
 
+#include <QDebug>
+#include <QTest>
+
 const QString TestCppcheckLibraryData::TempCfgFile = "./tmp.cfg";
 
 void TestCppcheckLibraryData::init()
diff --git a/gui/test/cppchecklibrarydata/testcppchecklibrarydata.h b/gui/test/cppchecklibrarydata/testcppchecklibrarydata.h
index fdc1120f9..dfaa0c674 100644
--- a/gui/test/cppchecklibrarydata/testcppchecklibrarydata.h
+++ b/gui/test/cppchecklibrarydata/testcppchecklibrarydata.h
@@ -18,7 +18,7 @@
 
 #include "cppchecklibrarydata.h"
 
-#include <QtTest/QtTest>
+#include <QObject>
 
 class TestCppcheckLibraryData : public QObject {
     Q_OBJECT
diff --git a/gui/test/filelist/testfilelist.cpp b/gui/test/filelist/testfilelist.cpp
index 51dc9bea0..c0f25fa22 100644
--- a/gui/test/filelist/testfilelist.cpp
+++ b/gui/test/filelist/testfilelist.cpp
@@ -21,8 +21,8 @@
 #include "filelist.h"
 
 #include <QDir>
-#include <QObject>
 #include <QString>
+#include <QTest>
 
 void TestFileList::addFile()
 {
diff --git a/gui/test/filelist/testfilelist.h b/gui/test/filelist/testfilelist.h
index 698d60569..61e579d0b 100644
--- a/gui/test/filelist/testfilelist.h
+++ b/gui/test/filelist/testfilelist.h
@@ -17,7 +17,6 @@
  */
 
 #include <QObject>
-#include <QtTest/QtTest>
 
 class TestFileList : public QObject {
     Q_OBJECT
diff --git a/gui/test/projectfile/testprojectfile.cpp b/gui/test/projectfile/testprojectfile.cpp
index e913780fc..52ce479c3 100644
--- a/gui/test/projectfile/testprojectfile.cpp
+++ b/gui/test/projectfile/testprojectfile.cpp
@@ -21,7 +21,7 @@
 #include "projectfile.h"
 #include "settings.h"
 
-#include <QObject>
+#include <QtTest>
 
 // Mock...
 const char Settings::SafeChecks::XmlRootName[] = "safe-checks";
diff --git a/gui/test/projectfile/testprojectfile.h b/gui/test/projectfile/testprojectfile.h
index 31a49ebd4..ac01d5b54 100644
--- a/gui/test/projectfile/testprojectfile.h
+++ b/gui/test/projectfile/testprojectfile.h
@@ -17,7 +17,6 @@
  */
 
 #include <QObject>
-#include <QtTest/QtTest>
 
 class TestProjectFile : public QObject {
     Q_OBJECT
diff --git a/gui/test/translationhandler/testtranslationhandler.cpp b/gui/test/translationhandler/testtranslationhandler.cpp
index a3d188aab..b09935ce0 100644
--- a/gui/test/translationhandler/testtranslationhandler.cpp
+++ b/gui/test/translationhandler/testtranslationhandler.cpp
@@ -20,7 +20,7 @@
 
 #include "translationhandler.h"
 
-#include <QObject>
+#include <QtTest>
 
 static const QStringList getTranslationNames(const TranslationHandler& handler)
 {
diff --git a/gui/test/translationhandler/testtranslationhandler.h b/gui/test/translationhandler/testtranslationhandler.h
index 534890003..c18308b89 100644
--- a/gui/test/translationhandler/testtranslationhandler.h
+++ b/gui/test/translationhandler/testtranslationhandler.h
@@ -17,7 +17,6 @@
  */
 
 #include <QObject>
-#include <QtTest/QtTest>
 
 class TestTranslationHandler : public QObject {
     Q_OBJECT
diff --git a/gui/test/xmlreportv2/testxmlreportv2.cpp b/gui/test/xmlreportv2/testxmlreportv2.cpp
index c06c538c7..07496962d 100644
--- a/gui/test/xmlreportv2/testxmlreportv2.cpp
+++ b/gui/test/xmlreportv2/testxmlreportv2.cpp
@@ -21,7 +21,7 @@
 #include "erroritem.h"
 #include "xmlreportv2.h"
 
-#include <QObject>
+#include <QtTest>
 
 void TestXmlReportV2::readXml()
 {
diff --git a/gui/test/xmlreportv2/testxmlreportv2.h b/gui/test/xmlreportv2/testxmlreportv2.h
index 754f697d3..b78b50f4b 100644
--- a/gui/test/xmlreportv2/testxmlreportv2.h
+++ b/gui/test/xmlreportv2/testxmlreportv2.h
@@ -16,7 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <QtTest/QtTest>
 #include <QObject>
 
 class TestXmlReportV2 : public QObject {
diff --git a/gui/translationhandler.h b/gui/translationhandler.h
index 4e644bc18..2593fc962 100644
--- a/gui/translationhandler.h
+++ b/gui/translationhandler.h
@@ -21,7 +21,6 @@
 
 #include <QList>
 #include <QObject>
-#include <QStringList>
 
 class QTranslator;
 
diff --git a/tools/dmake.cpp b/tools/dmake.cpp
index 9d41c53b1..351ef33f9 100644
--- a/tools/dmake.cpp
+++ b/tools/dmake.cpp
@@ -19,7 +19,7 @@
 // Generate Makefile for cppcheck
 
 #include <algorithm>
-#include <fstream>
+#include <fstream> // IWYU pragma: keep
 #include <iostream>
 #include <string>
 #include <vector>