diff --git a/cli/cli.cpp b/cli/cli.cpp
index 8df48b3..c381a60 100644
--- a/cli/cli.cpp
+++ b/cli/cli.cpp
@@ -19,10 +19,8 @@
 
 using namespace std;
 using namespace std::placeholders;
-using namespace ApplicationUtilities;
-using namespace ConversionUtilities;
-using namespace EscapeCodes;
-using namespace IoUtilities;
+using namespace CppUtilities;
+using namespace CppUtilities::EscapeCodes;
 using namespace Io;
 
 namespace Cli {
diff --git a/gui/initiategui.h b/gui/initiategui.h
index 96a4df4..f4f4ba0 100644
--- a/gui/initiategui.h
+++ b/gui/initiategui.h
@@ -5,13 +5,13 @@
 
 QT_FORWARD_DECLARE_CLASS(QString)
 
-namespace ApplicationUtilities {
+namespace CppUtilities {
 class QtConfigArguments;
 }
 
 namespace QtGui {
 
-int runWidgetsGui(int argc, char *argv[], const ApplicationUtilities::QtConfigArguments &qtConfigArgs, const QString &file);
+int runWidgetsGui(int argc, char *argv[], const CppUtilities::QtConfigArguments &qtConfigArgs, const QString &file);
 }
 
 #endif // INITIATE_H
diff --git a/gui/initiatequi.cpp b/gui/initiatequi.cpp
index 6690278..bd03ae5 100644
--- a/gui/initiatequi.cpp
+++ b/gui/initiatequi.cpp
@@ -13,8 +13,8 @@
 #include <QFile>
 #include <QSettings>
 
-using namespace ApplicationUtilities;
-using namespace Dialogs;
+using namespace CppUtilities;
+using namespace QtUtilities;
 
 namespace QtGui {
 
diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
index bf689aa..a6af83d 100644
--- a/gui/mainwindow.cpp
+++ b/gui/mainwindow.cpp
@@ -42,10 +42,9 @@
 #include <stdexcept>
 
 using namespace std;
-using namespace IoUtilities;
+using namespace CppUtilities;
+using namespace QtUtilities;
 using namespace Io;
-using namespace Dialogs;
-using namespace MiscUtils;
 
 namespace QtGui {
 
@@ -110,7 +109,7 @@ void MainWindow::setSomethingChanged(bool somethingChanged)
 /*!
  * \brief Constructs a new main window.
  */
-MainWindow::MainWindow(QSettings &settings, Dialogs::QtSettings *qtSettings, QWidget *parent)
+MainWindow::MainWindow(QSettings &settings, QtUtilities::QtSettings *qtSettings, QWidget *parent)
     : QMainWindow(parent)
     , m_ui(new Ui::MainWindow)
     , m_openFlags(PasswordFileOpenFlags::None)
@@ -413,8 +412,6 @@ void MainWindow::showUndoView()
  */
 bool MainWindow::openFile(const QString &path, PasswordFileOpenFlags openFlags)
 {
-    using namespace Dialogs;
-
     // close previous file
     if (m_file.hasRootEntry() && !closeFile()) {
         return false;
@@ -596,21 +593,21 @@ void MainWindow::updateUiStatus()
  */
 void MainWindow::updateWindowTitle()
 {
-    Dialogs::DocumentStatus docStatus;
+    DocumentStatus docStatus;
     if (m_file.hasRootEntry()) {
         if (m_somethingChanged) {
-            docStatus = Dialogs::DocumentStatus::Unsaved;
+            docStatus = DocumentStatus::Unsaved;
         } else {
-            docStatus = Dialogs::DocumentStatus::Saved;
+            docStatus = DocumentStatus::Saved;
         }
     } else {
-        docStatus = Dialogs::DocumentStatus::NoDocument;
+        docStatus = DocumentStatus::NoDocument;
     }
     auto documentPath(QString::fromStdString(m_file.path()));
     if (m_openFlags & PasswordFileOpenFlags::ReadOnly) {
         documentPath += tr(" [read-only]");
     }
-    setWindowTitle(Dialogs::generateWindowTitle(docStatus, documentPath));
+    setWindowTitle(generateWindowTitle(docStatus, documentPath));
 }
 
 void MainWindow::applyDefaultExpanding(const QModelIndex &parent)
@@ -817,7 +814,6 @@ bool MainWindow::closeFile()
  */
 bool MainWindow::saveFile()
 {
-    using namespace Dialogs;
     if (showNoFileOpened()) {
         return false;
     }
@@ -922,7 +918,7 @@ void MainWindow::showContainingDirectory()
     }
     const QFileInfo file(QString::fromStdString(m_file.path()));
     if (file.dir().exists()) {
-        DesktopUtils::openLocalFileOrDir(file.dir().absolutePath());
+        openLocalFileOrDir(file.dir().absolutePath());
     }
 }
 
@@ -1131,7 +1127,6 @@ void MainWindow::setPasswordVisibility(QAction *selectedAction)
  */
 void MainWindow::changePassword()
 {
-    using namespace Dialogs;
     if (showNoFileOpened()) {
         return;
     }
@@ -1217,7 +1212,7 @@ void MainWindow::showTableViewContextMenu()
         if (const Field *field = m_fieldModel->field(static_cast<size_t>(index.row()))) {
             if (url.isEmpty() && field->type() != FieldType::Password) {
                 for (const string &protocol : protocols) {
-                    if (ConversionUtilities::startsWith(field->value(), protocol)) {
+                    if (startsWith(field->value(), protocol)) {
                         url = QString::fromUtf8(field->value().data());
                     }
                 }
diff --git a/gui/mainwindow.h b/gui/mainwindow.h
index 686baee..afc839b 100644
--- a/gui/mainwindow.h
+++ b/gui/mainwindow.h
@@ -20,19 +20,16 @@ QT_FORWARD_DECLARE_CLASS(QUndoView)
 QT_FORWARD_DECLARE_CLASS(QSettings)
 
 namespace Io {
-DECLARE_ENUM_CLASS(EntryType, int);
-DECLARE_ENUM_CLASS(FieldType, int);
+enum class EntryType : int;
+enum class FieldType : int;
 } // namespace Io
 
-namespace MiscUtils {
+namespace QtUtilities {
 class RecentMenuManager;
-}
-
-namespace Dialogs {
 class AboutDialog;
 class SettingsDialog;
 class QtSettings;
-} // namespace Dialogs
+} // namespace QtUtilities
 
 namespace QtGui {
 
@@ -48,7 +45,7 @@ class MainWindow : public QMainWindow {
     Q_OBJECT
 
 public:
-    explicit MainWindow(QSettings &settings, Dialogs::QtSettings *qtSettings = nullptr, QWidget *parent = nullptr);
+    explicit MainWindow(QSettings &settings, QtUtilities::QtSettings *qtSettings = nullptr, QWidget *parent = nullptr);
     ~MainWindow() override;
 
 public slots:
@@ -129,11 +126,11 @@ private:
     Io::PasswordFileOpenFlags m_openFlags;
     bool m_dontUpdateSelection;
     int m_clearClipboardTimer;
-    MiscUtils::RecentMenuManager *m_recentMgr;
-    Dialogs::AboutDialog *m_aboutDlg;
+    QtUtilities::RecentMenuManager *m_recentMgr;
+    QtUtilities::AboutDialog *m_aboutDlg;
     QSettings &m_settings;
-    Dialogs::QtSettings *m_qtSettings;
-    Dialogs::SettingsDialog *m_settingsDlg;
+    QtUtilities::QtSettings *m_qtSettings;
+    QtUtilities::SettingsDialog *m_settingsDlg;
 };
 
 /*!
diff --git a/gui/mainwindow.ui b/gui/mainwindow.ui
index 58fbcfa..058dae2 100644
--- a/gui/mainwindow.ui
+++ b/gui/mainwindow.ui
@@ -76,7 +76,7 @@
             <number>0</number>
            </property>
            <item>
-            <widget class="Widgets::ClearLineEdit" name="accountFilterLineEdit">
+            <widget class="QtUtilities::ClearLineEdit" name="accountFilterLineEdit">
              <property name="sizePolicy">
               <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
                <horstretch>0</horstretch>
@@ -573,7 +573,7 @@
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>
   <customwidget>
-   <class>Widgets::ClearLineEdit</class>
+   <class>QtUtilities::ClearLineEdit</class>
    <extends>QLineEdit</extends>
    <header location="global">qtutilities/widgets/clearlineedit.h</header>
   </customwidget>
diff --git a/gui/passwordgeneratordialog.cpp b/gui/passwordgeneratordialog.cpp
index 61587e3..0ffbe71 100644
--- a/gui/passwordgeneratordialog.cpp
+++ b/gui/passwordgeneratordialog.cpp
@@ -19,7 +19,7 @@
 using namespace std;
 using namespace Io;
 using namespace Util;
-using namespace Dialogs;
+using namespace QtUtilities;
 
 namespace QtGui {
 
diff --git a/main.cpp b/main.cpp
index f0e86ef..ac2db0c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -13,7 +13,7 @@
 
 #include <c++utilities/application/argumentparser.h>
 #include <c++utilities/application/commandlineutils.h>
-#include <c++utilities/application/failure.h>
+#include <c++utilities/misc/parseerror.h>
 
 #if defined(PASSWORD_MANAGER_GUI_QTWIDGETS) || defined(PASSWORD_MANAGER_GUI_QTQUICK)
 #include <QString>
@@ -35,7 +35,7 @@ ENABLE_QT_RESOURCES_OF_STATIC_DEPENDENCIES
 #endif
 
 using namespace std;
-using namespace ApplicationUtilities;
+using namespace CppUtilities;
 using namespace Util;
 
 int main(int argc, char *argv[])
@@ -65,7 +65,7 @@ int main(int argc, char *argv[])
     HelpArgument helpArg(parser);
     parser.setMainArguments({ &qtConfigArgs.qtWidgetsGuiArg(), &qtConfigArgs.qtQuickGuiArg(), &cliArg, &helpArg });
     // parse the specified arguments
-    parser.parseArgsOrExit(argc, argv);
+    parser.parseArgs(argc, argv);
 #endif
 
     // init OpenSSL
diff --git a/quickgui/controller.cpp b/quickgui/controller.cpp
index fd7fb84..5ec5e6f 100644
--- a/quickgui/controller.cpp
+++ b/quickgui/controller.cpp
@@ -27,8 +27,8 @@
 
 using namespace std;
 using namespace Io;
-using namespace IoUtilities;
-using namespace Dialogs;
+using namespace CppUtilities;
+using namespace QtUtilities;
 
 namespace QtGui {
 
@@ -89,7 +89,7 @@ void Controller::setFilePath(const QString &filePath)
     // assign full file path and file name
     m_file.clear();
     m_file.setPath(filePath.toLocal8Bit().data());
-    m_fileName = QString::fromLocal8Bit(IoUtilities::fileName(m_file.path()).data());
+    m_fileName = QString::fromLocal8Bit(CppUtilities::fileName(m_file.path()).data());
     emit filePathChanged(m_filePath = filePath);
 
     // clear password so we don't use the password from the previous file
diff --git a/quickgui/initiatequick.cpp b/quickgui/initiatequick.cpp
index a0a1215..2e7a8cc 100644
--- a/quickgui/initiatequick.cpp
+++ b/quickgui/initiatequick.cpp
@@ -29,7 +29,7 @@
 #include <QApplication>
 #endif
 
-using namespace ApplicationUtilities;
+using namespace CppUtilities;
 
 namespace QtGui {
 
diff --git a/quickgui/initiatequick.h b/quickgui/initiatequick.h
index 26fd5ec..2e2ceb3 100644
--- a/quickgui/initiatequick.h
+++ b/quickgui/initiatequick.h
@@ -5,13 +5,13 @@
 
 QT_FORWARD_DECLARE_CLASS(QString)
 
-namespace ApplicationUtilities {
+namespace CppUtilities {
 class QtConfigArguments;
 }
 
 namespace QtGui {
 
-int runQuickGui(int argc, char *argv[], const ApplicationUtilities::QtConfigArguments &qtConfigArgs, const QString &file);
+int runQuickGui(int argc, char *argv[], const CppUtilities::QtConfigArguments &qtConfigArgs, const QString &file);
 }
 
 #endif // QT_QUICK_GUI_INITIATE_H