diff --git a/avogadro/qtplugins/yaehmop/banddialog.cpp b/avogadro/qtplugins/yaehmop/banddialog.cpp
index e8a9d9bd08..3bbfad3d8e 100644
--- a/avogadro/qtplugins/yaehmop/banddialog.cpp
+++ b/avogadro/qtplugins/yaehmop/banddialog.cpp
@@ -4,12 +4,12 @@
 ******************************************************************************/
 
 #include "banddialog.h"
+
 #include "ui_banddialog.h"
 
 #include <QSettings>
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 BandDialog::BandDialog(QWidget* aParent, YaehmopSettings& yaehmopSettings)
   : QDialog(aParent), m_ui(new Ui::BandDialog),
@@ -18,6 +18,9 @@ BandDialog::BandDialog(QWidget* aParent, YaehmopSettings& yaehmopSettings)
   m_ui->setupUi(this);
 }
 
+// Destructor must be defined after Ui::BandDialog has been resovled
+BandDialog::~BandDialog() = default;
+
 int BandDialog::exec()
 {
   // Load the settings then exec
@@ -54,5 +57,4 @@ void BandDialog::accept()
   QDialog::accept();
 }
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
diff --git a/avogadro/qtplugins/yaehmop/banddialog.h b/avogadro/qtplugins/yaehmop/banddialog.h
index 684f8e37d7..8ed7c76b77 100644
--- a/avogadro/qtplugins/yaehmop/banddialog.h
+++ b/avogadro/qtplugins/yaehmop/banddialog.h
@@ -6,14 +6,13 @@
 #ifndef AVOGADRO_QTPLUGINS_YAEHMOPBANDDIALOG_H
 #define AVOGADRO_QTPLUGINS_YAEHMOPBANDDIALOG_H
 
-#include <memory>
+#include "yaehmopsettings.h"
 
 #include <QDialog>
 
-#include "yaehmopsettings.h"
+#include <memory>
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 namespace Ui {
 class BandDialog;
@@ -28,7 +27,7 @@ class BandDialog : public QDialog
 
 public:
   explicit BandDialog(QWidget* parent, YaehmopSettings& yaehmopSettings);
-  ~BandDialog() = default;
+  ~BandDialog();
 
 public slots:
   int exec() override;
@@ -41,6 +40,6 @@ protected slots:
   YaehmopSettings& m_yaehmopSettings;
 };
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
+
 #endif // AVOGADRO_QTPLUGINS_YAEHMOPBANDDIALOG_H
diff --git a/avogadro/qtplugins/yaehmop/specialkpointsdata.h b/avogadro/qtplugins/yaehmop/specialkpointsdata.h
index cdd6d6d719..63abb7aa1c 100644
--- a/avogadro/qtplugins/yaehmop/specialkpointsdata.h
+++ b/avogadro/qtplugins/yaehmop/specialkpointsdata.h
@@ -6,8 +6,7 @@
 #ifndef AVOGADRO_QTPLUGINS_YAEHMOP_SPECIALKPOINTSDATA_H
 #define AVOGADRO_QTPLUGINS_YAEHMOP_SPECIALKPOINTSDATA_H
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 // There are 230 of these (not including the first value, which is null)
 // One point for each space group.
@@ -392,7 +391,6 @@ const char* special_k_points[] = {
   "GM 0 0 0,H 0.5 -0.5 0.5,P 0.25 0.25 0.25,N 0 0 0.5"  // 230
 };
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
 
 #endif
diff --git a/avogadro/qtplugins/yaehmop/yaehmop.cpp b/avogadro/qtplugins/yaehmop/yaehmop.cpp
index c48278e46f..6eb16bb84f 100644
--- a/avogadro/qtplugins/yaehmop/yaehmop.cpp
+++ b/avogadro/qtplugins/yaehmop/yaehmop.cpp
@@ -3,6 +3,20 @@
   This source code is released under the 3-Clause BSD License, (see "LICENSE").
 ******************************************************************************/
 
+#include "yaehmop.h"
+
+#include "banddialog.h"
+#include "specialkpoints.h"
+#include "yaehmopout.h"
+
+#include <avogadro/core/array.h>
+#include <avogadro/core/elements.h>
+#include <avogadro/core/unitcell.h>
+#include <avogadro/core/vector.h>
+#include <avogadro/qtgui/molecule.h>
+#include <avogadro/vtk/chartdialog.h>
+#include <avogadro/vtk/chartwidget.h>
+
 #include <QAction>
 #include <QByteArray>
 #include <QCoreApplication>
@@ -17,20 +31,6 @@
 #include <QTextEdit>
 #include <QVBoxLayout>
 
-#include <avogadro/core/array.h>
-#include <avogadro/core/elements.h>
-#include <avogadro/core/unitcell.h>
-#include <avogadro/core/vector.h>
-#include <avogadro/qtgui/molecule.h>
-#include <avogadro/vtk/chartdialog.h>
-#include <avogadro/vtk/chartwidget.h>
-
-#include "banddialog.h"
-#include "specialkpoints.h"
-#include "yaehmopout.h"
-
-#include "yaehmop.h"
-
 using Avogadro::Vector3;
 using Avogadro::Vector3i;
 using Avogadro::Core::Array;
@@ -38,8 +38,7 @@ using Avogadro::Core::Elements;
 using Avogadro::Core::UnitCell;
 using Avogadro::QtGui::Molecule;
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 Yaehmop::Yaehmop(QObject* parent_)
   : Avogadro::QtGui::ExtensionPlugin(parent_), m_actions(QList<QAction*>()),
@@ -132,7 +131,7 @@ void Yaehmop::moleculeChanged(unsigned int c)
 {
   Q_ASSERT(m_molecule == qobject_cast<Molecule*>(sender()));
 
-  Molecule::MoleculeChanges changes = static_cast<Molecule::MoleculeChanges>(c);
+  auto changes = static_cast<Molecule::MoleculeChanges>(c);
 
   if (changes & Molecule::UnitCell) {
     if (changes & Molecule::Added || changes & Molecule::Removed)
@@ -586,15 +585,15 @@ bool Yaehmop::executeYaehmop(const QByteArray& input, QByteArray& output,
 
 void Yaehmop::showYaehmopInput(const QString& input)
 {
-  QDialog* dialog = new QDialog(qobject_cast<QWidget*>(this->parent()));
+  auto* dialog = new QDialog(qobject_cast<QWidget*>(this->parent()));
 
   // Make sure this gets deleted upon closing
   dialog->setAttribute(Qt::WA_DeleteOnClose);
 
-  QVBoxLayout* layout = new QVBoxLayout(dialog);
+  auto* layout = new QVBoxLayout(dialog);
   dialog->setLayout(layout);
   dialog->setWindowTitle(tr("Yaehmop Input"));
-  QTextEdit* edit = new QTextEdit(dialog);
+  auto* edit = new QTextEdit(dialog);
   layout->addWidget(edit);
   dialog->resize(500, 500);
 
@@ -603,5 +602,4 @@ void Yaehmop::showYaehmopInput(const QString& input)
   dialog->show();
 }
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
diff --git a/avogadro/qtplugins/yaehmop/yaehmop.h b/avogadro/qtplugins/yaehmop/yaehmop.h
index 3782ae8f95..6256377f2b 100644
--- a/avogadro/qtplugins/yaehmop/yaehmop.h
+++ b/avogadro/qtplugins/yaehmop/yaehmop.h
@@ -6,14 +6,15 @@
 #ifndef AVOGADRO_QTPLUGINS_YAEHMOP_H
 #define AVOGADRO_QTPLUGINS_YAEHMOP_H
 
+#include "banddialog.h"
+#include "yaehmopsettings.h"
+
 #include <avogadro/qtgui/extensionplugin.h>
 
 #include <avogadro/core/vector.h>
 
 #include <memory>
 
-#include "yaehmopsettings.h"
-
 // Forward declarations
 class QByteArray;
 
@@ -21,10 +22,7 @@ namespace VTK {
 class ChartDialog;
 }
 
-namespace Avogadro {
-namespace QtPlugins {
-
-class BandDialog;
+namespace Avogadro::QtPlugins {
 
 /**
  * @brief Perform extended Hückel calculations with yaehmop.
@@ -36,13 +34,13 @@ class Yaehmop : public Avogadro::QtGui::ExtensionPlugin
   explicit Yaehmop(QObject* parent_ = nullptr);
   ~Yaehmop();
 
-  QString name() const { return tr("Yaehmop"); }
-  QString description() const;
-  QList<QAction*> actions() const;
-  QStringList menuPath(QAction*) const;
+  QString name() const override { return tr("Yaehmop"); }
+  QString description() const override;
+  QList<QAction*> actions() const override;
+  QStringList menuPath(QAction*) const override;
 
 public slots:
-  void setMolecule(QtGui::Molecule* mol);
+  void setMolecule(QtGui::Molecule* mol) override;
 
   void moleculeChanged(unsigned int changes);
 
@@ -88,7 +86,6 @@ inline QString Yaehmop::description() const
   return tr("Perform extended Hückel calculations with yaehmop.");
 }
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
 
 #endif // AVOGADRO_QTPLUGINS_YAEHMOPEXTENSION_H
diff --git a/avogadro/qtplugins/yaehmop/yaehmopout.cpp b/avogadro/qtplugins/yaehmop/yaehmopout.cpp
index 1eacfa2fe4..48c3171263 100644
--- a/avogadro/qtplugins/yaehmop/yaehmopout.cpp
+++ b/avogadro/qtplugins/yaehmop/yaehmopout.cpp
@@ -5,15 +5,14 @@
 
 #include "yaehmopout.h"
 
+#include <avogadro/core/vector.h>
+
 #include <QDebug>
 #include <QRegularExpression>
 #include <QString>
 #include <QVector>
 
-#include <avogadro/core/vector.h>
-
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 inline bool printAndReturnFalse(const QString& error)
 {
@@ -134,5 +133,4 @@ bool YaehmopOut::readBandData(const QString& data,
   return true;
 }
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
diff --git a/avogadro/qtplugins/yaehmop/yaehmopout.h b/avogadro/qtplugins/yaehmop/yaehmopout.h
index 0e26440dbb..87ce2b25ec 100644
--- a/avogadro/qtplugins/yaehmop/yaehmopout.h
+++ b/avogadro/qtplugins/yaehmop/yaehmopout.h
@@ -11,14 +11,13 @@
 
 #include <avogadro/core/vector.h>
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
-typedef struct
+using specialKPoint = struct
 {
   QString label;
   Vector3 coords;
-} specialKPoint;
+};
 
 // Static class for Yaehmop output
 class YaehmopOut
@@ -34,7 +33,6 @@ class YaehmopOut
                            QVector<specialKPoint>& specialKPoints);
 };
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
 
 #endif // AVOGADRO_QTPLUGINS_YAEHMOPOUT_H
diff --git a/avogadro/qtplugins/yaehmop/yaehmopsettings.h b/avogadro/qtplugins/yaehmop/yaehmopsettings.h
index b2de520eb9..991fb8d68e 100644
--- a/avogadro/qtplugins/yaehmop/yaehmopsettings.h
+++ b/avogadro/qtplugins/yaehmop/yaehmopsettings.h
@@ -8,8 +8,7 @@
 
 #include <QString>
 
-namespace Avogadro {
-namespace QtPlugins {
+namespace Avogadro::QtPlugins {
 
 static const char* YAEHMOP_DEFAULT_SPECIAL_KPOINTS = "GM 0 0 0";
 
@@ -32,6 +31,6 @@ struct YaehmopSettings
   unsigned short numDim;
 };
 
-} // namespace QtPlugins
-} // namespace Avogadro
+} // namespace Avogadro::QtPlugins
+
 #endif // AVOGADRO_QTPLUGINS_YAEHMOPSETTINGS_H
diff --git a/tests/core/elementtest.cpp b/tests/core/elementtest.cpp
index f0eb76114a..6f06f4920a 100644
--- a/tests/core/elementtest.cpp
+++ b/tests/core/elementtest.cpp
@@ -16,6 +16,7 @@
 
 #include <gtest/gtest.h>
 
+#include <avogadro/core/avogadrocore.h>
 #include <avogadro/core/elements.h>
 #include <avogadro/core/utilities.h>