diff --git a/src/conf/CMakeLists.txt b/src/conf/CMakeLists.txt
index 1e969c484..6d1fd11a8 100644
--- a/src/conf/CMakeLists.txt
+++ b/src/conf/CMakeLists.txt
@@ -1,75 +1,77 @@
 include_directories(${kleopatra_SOURCE_DIR}/src)
 
 
 set(_kcm_kleopatra_libkleopatraclient_extra_SRCS
   smimevalidationconfigurationwidget.cpp
   smimevalidationconfigurationpage.cpp
   cryptooperationsconfigwidget.cpp
   cryptooperationsconfigpage.cpp
   smimevalidationconfigurationwidget.h
   smimevalidationconfigurationpage.h
   cryptooperationsconfigwidget.h
   cryptooperationsconfigpage.h
   smartcardconfigpage.cpp
   smartcardconfigpage.h
 )
 
 ki18n_wrap_ui(_kcm_kleopatra_libkleopatraclient_extra_SRCS
   smimevalidationconfigurationwidget.ui
 )
 
 kconfig_add_kcfg_files(_kcm_kleopatra_libkleopatraclient_extra_SRCS
   ${kleopatra_SOURCE_DIR}/src/kcfg/smimevalidationpreferences.kcfgc
 )
 
 set(_kcm_kleopatra_libkleopatraclient_extra_LIBS kleopatraclientgui)
 
 
 set(kcm_kleopatra_PART_SRCS
   dirservconfigpage.cpp
   appearanceconfigpage.cpp
   appearanceconfigwidget.cpp
   gnupgsystemconfigurationpage.cpp
   dirservconfigpage.h
   appearanceconfigpage.h
   appearanceconfigwidget.h
   gnupgsystemconfigurationpage.h
   labelledwidget.cpp labelledwidget.h
   labelledwidget.cpp labelledwidget.h
+  pluralhandlingspinbox.cpp
+  pluralhandlingspinbox.h
   ${kleopatra_BINARY_DIR}/src/kleopatra_debug.cpp
   ${_kcm_kleopatra_libkleopatraclient_extra_SRCS}
 )
 
 
 ki18n_wrap_ui(kcm_kleopatra_PART_SRCS
   smimevalidationconfigurationwidget.ui
 )
 
 kconfig_add_kcfg_files(kcm_kleopatra_PART_SRCS
   ${kleopatra_SOURCE_DIR}/src/kcfg/tooltippreferences.kcfgc
   ${kleopatra_SOURCE_DIR}/src/kcfg/emailoperationspreferences.kcfgc
   ${kleopatra_SOURCE_DIR}/src/kcfg/fileoperationspreferences.kcfgc
   ${kleopatra_SOURCE_DIR}/src/kcfg/tagspreferences.kcfgc
   ${kleopatra_SOURCE_DIR}/src/kcfg/settings.kcfgc
 )
 
 add_library(kcm_kleopatra_static STATIC ${kcm_kleopatra_PART_SRCS})
 set_property(TARGET kcm_kleopatra_static PROPERTY POSITION_INDEPENDENT_CODE ON)
 
 target_link_libraries(kcm_kleopatra_static
   KPim${KF_MAJOR_VERSION}::Libkleo
   KF${KF_MAJOR_VERSION}::I18n
   KF${KF_MAJOR_VERSION}::IconThemes
   KF${KF_MAJOR_VERSION}::KCMUtils
   KF${KF_MAJOR_VERSION}::WidgetsAddons
   ${_kcm_kleopatra_extra_libs}
   ${_kleopatra_dbusaddons_libs}
   ${_kcm_kleopatra_libkleopatraclient_extra_LIBS}
 )
 
 if (NOT WIN32)
   add_library(kleopatra_config_gnupgsystem MODULE kcm_gnupgsystemconfigurationpage.cpp)
   target_link_libraries(kleopatra_config_gnupgsystem kcm_kleopatra_static KF${KF_MAJOR_VERSION}::CoreAddons)
 
   install(TARGETS kleopatra_config_gnupgsystem DESTINATION ${KDE_INSTALL_PLUGINDIR}/pim${QT_MAJOR_VERSION}/kcms/kleopatra)
 endif()
diff --git a/src/conf/pluralhandlingspinbox.cpp b/src/conf/pluralhandlingspinbox.cpp
new file mode 100644
index 000000000..7f306b21a
--- /dev/null
+++ b/src/conf/pluralhandlingspinbox.cpp
@@ -0,0 +1,52 @@
+/*
+    SPDX-FileCopyrightText: 2014 Laurent Montel <montel@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.1-or-later
+
+    This is a copy of KPluralHandlingSpinBox from KTextWidgets.
+*/
+
+#include "pluralhandlingspinbox.h"
+
+class PluralHandlingSpinBoxPrivate
+{
+public:
+    PluralHandlingSpinBoxPrivate(QSpinBox *q)
+        : q(q)
+    {
+        QObject::connect(q, &QSpinBox::valueChanged, q, [this](int value) {
+            updateSuffix(value);
+        });
+    }
+
+    void updateSuffix(int value)
+    {
+        if (!pluralSuffix.isEmpty()) {
+            KLocalizedString s = pluralSuffix;
+            q->setSuffix(s.subs(value).toString());
+        }
+    }
+
+    QSpinBox *const q;
+    KLocalizedString pluralSuffix;
+};
+
+PluralHandlingSpinBox::PluralHandlingSpinBox(QWidget *parent)
+    : QSpinBox(parent)
+    , d(new PluralHandlingSpinBoxPrivate(this))
+{
+}
+
+PluralHandlingSpinBox::~PluralHandlingSpinBox() = default;
+
+void PluralHandlingSpinBox::setSuffix(const KLocalizedString &suffix)
+{
+    d->pluralSuffix = suffix;
+    if (suffix.isEmpty()) {
+        QSpinBox::setSuffix(QString());
+    } else {
+        d->updateSuffix(value());
+    }
+}
+
+#include "moc_pluralhandlingspinbox.cpp"
diff --git a/src/conf/pluralhandlingspinbox.h b/src/conf/pluralhandlingspinbox.h
new file mode 100644
index 000000000..5c7023440
--- /dev/null
+++ b/src/conf/pluralhandlingspinbox.h
@@ -0,0 +1,39 @@
+/*
+    SPDX-FileCopyrightText: 2014 Laurent Montel <montel@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.1-or-later
+
+    This is a copy of KPluralHandlingSpinBox from KTextWidgets.
+*/
+
+#pragma once
+
+#include <KLocalizedString>
+
+#include <QSpinBox>
+
+#include <memory>
+
+class PluralHandlingSpinBox : public QSpinBox
+{
+    Q_OBJECT
+public:
+    /**
+     * Default constructor
+     */
+
+    explicit PluralHandlingSpinBox(QWidget *parent = nullptr);
+    ~PluralHandlingSpinBox() override;
+
+    /**
+     * Sets the suffix to @p suffix.
+     * Use this to add a plural-aware suffix, e.g. by using ki18np("singular", "plural").
+     */
+    void setSuffix(const KLocalizedString &suffix);
+
+private:
+    friend class PluralHandlingSpinBoxPrivate;
+    std::unique_ptr<class PluralHandlingSpinBoxPrivate> const d;
+
+    Q_DISABLE_COPY(PluralHandlingSpinBox)
+};