diff --git a/src/base/bittorrent/infohash.cpp b/src/base/bittorrent/infohash.cpp
index 29f7c0cda0c..495a4f47dab 100644
--- a/src/base/bittorrent/infohash.cpp
+++ b/src/base/bittorrent/infohash.cpp
@@ -35,11 +35,6 @@ using namespace BitTorrent;
 
 const int InfoHashTypeId = qRegisterMetaType<InfoHash>();
 
-InfoHash::InfoHash()
-    : m_valid(false)
-{
-}
-
 InfoHash::InfoHash(const lt::sha1_hash &nativeHash)
     : m_valid(true)
     , m_nativeHash(nativeHash)
diff --git a/src/base/bittorrent/infohash.h b/src/base/bittorrent/infohash.h
index f015f384188..be0a0ef7581 100644
--- a/src/base/bittorrent/infohash.h
+++ b/src/base/bittorrent/infohash.h
@@ -38,7 +38,7 @@ namespace BitTorrent
     class InfoHash
     {
     public:
-        InfoHash();
+        InfoHash() = default;
         InfoHash(const lt::sha1_hash &nativeHash);
         InfoHash(const QString &hashString);
         InfoHash(const InfoHash &other) = default;
@@ -54,7 +54,7 @@ namespace BitTorrent
         operator QString() const;
 
     private:
-        bool m_valid;
+        bool m_valid = false;
         lt::sha1_hash m_nativeHash;
         QString m_hashString;
     };
diff --git a/src/base/torrentfilter.cpp b/src/base/torrentfilter.cpp
index f692f62847a..1c4dcaa7dfb 100644
--- a/src/base/torrentfilter.cpp
+++ b/src/base/torrentfilter.cpp
@@ -32,7 +32,7 @@
 #include "bittorrent/torrenthandle.h"
 
 const QString TorrentFilter::AnyCategory;
-const QStringSet TorrentFilter::AnyHash = (QStringSet() << QString());
+const InfoHashSet TorrentFilter::AnyHash {{}};
 const QString TorrentFilter::AnyTag;
 
 const TorrentFilter TorrentFilter::DownloadingTorrent(TorrentFilter::Downloading);
@@ -49,12 +49,7 @@ const TorrentFilter TorrentFilter::ErroredTorrent(TorrentFilter::Errored);
 
 using BitTorrent::TorrentHandle;
 
-TorrentFilter::TorrentFilter()
-    : m_type(All)
-{
-}
-
-TorrentFilter::TorrentFilter(const Type type, const QStringSet &hashSet, const QString &category, const QString &tag)
+TorrentFilter::TorrentFilter(const Type type, const InfoHashSet &hashSet, const QString &category, const QString &tag)
     : m_type(type)
     , m_category(category)
     , m_tag(tag)
@@ -62,7 +57,7 @@ TorrentFilter::TorrentFilter(const Type type, const QStringSet &hashSet, const Q
 {
 }
 
-TorrentFilter::TorrentFilter(const QString &filter, const QStringSet &hashSet, const QString &category, const QString &tag)
+TorrentFilter::TorrentFilter(const QString &filter, const InfoHashSet &hashSet, const QString &category, const QString &tag)
     : m_type(All)
     , m_category(category)
     , m_tag(tag)
@@ -112,7 +107,7 @@ bool TorrentFilter::setTypeByName(const QString &filter)
     return setType(type);
 }
 
-bool TorrentFilter::setHashSet(const QStringSet &hashSet)
+bool TorrentFilter::setHashSet(const InfoHashSet &hashSet)
 {
     if (m_hashSet != hashSet)
     {
diff --git a/src/base/torrentfilter.h b/src/base/torrentfilter.h
index 49344cff7ce..9136e8759b0 100644
--- a/src/base/torrentfilter.h
+++ b/src/base/torrentfilter.h
@@ -32,13 +32,15 @@
 #include <QSet>
 #include <QString>
 
-typedef QSet<QString> QStringSet;
+#include "base/bittorrent/infohash.h"
 
 namespace BitTorrent
 {
     class TorrentHandle;
 }
 
+using InfoHashSet = QSet<BitTorrent::InfoHash>;
+
 class TorrentFilter
 {
 public:
@@ -60,7 +62,7 @@ class TorrentFilter
 
     // These mean any permutation, including no category / tag.
     static const QString AnyCategory;
-    static const QStringSet AnyHash;
+    static const InfoHashSet AnyHash;
     static const QString AnyTag;
 
     static const TorrentFilter DownloadingTorrent;
@@ -75,15 +77,15 @@ class TorrentFilter
     static const TorrentFilter StalledDownloadingTorrent;
     static const TorrentFilter ErroredTorrent;
 
-    TorrentFilter();
+    TorrentFilter() = default;
     // category & tags: pass empty string for uncategorized / untagged torrents.
     // Pass null string (QString()) to disable filtering (i.e. all torrents).
-    TorrentFilter(Type type, const QStringSet &hashSet = AnyHash, const QString &category = AnyCategory, const QString &tag = AnyTag);
-    TorrentFilter(const QString &filter, const QStringSet &hashSet = AnyHash, const QString &category = AnyCategory, const QString &tags = AnyTag);
+    TorrentFilter(Type type, const InfoHashSet &hashSet = AnyHash, const QString &category = AnyCategory, const QString &tag = AnyTag);
+    TorrentFilter(const QString &filter, const InfoHashSet &hashSet = AnyHash, const QString &category = AnyCategory, const QString &tags = AnyTag);
 
     bool setType(Type type);
     bool setTypeByName(const QString &filter);
-    bool setHashSet(const QStringSet &hashSet);
+    bool setHashSet(const InfoHashSet &hashSet);
     bool setCategory(const QString &category);
     bool setTag(const QString &tag);
 
@@ -95,10 +97,10 @@ class TorrentFilter
     bool matchCategory(const BitTorrent::TorrentHandle *torrent) const;
     bool matchTag(const BitTorrent::TorrentHandle *torrent) const;
 
-    Type m_type;
+    Type m_type {All};
     QString m_category;
     QString m_tag;
-    QStringSet m_hashSet;
+    InfoHashSet m_hashSet;
 };
 
 #endif // TORRENTFILTER_H
diff --git a/src/gui/mainwindow.cpp b/src/gui/mainwindow.cpp
index 8cf58d3073a..0b777301f08 100644
--- a/src/gui/mainwindow.cpp
+++ b/src/gui/mainwindow.cpp
@@ -264,11 +264,11 @@ MainWindow::MainWindow(QWidget *parent)
     connect(BitTorrent::Session::instance(), &BitTorrent::Session::trackerlessStateChanged, m_transferListFiltersWidget, &TransferListFiltersWidget::changeTrackerless);
 
     connect(BitTorrent::Session::instance(), &BitTorrent::Session::trackerSuccess
-        , m_transferListFiltersWidget, qOverload<BitTorrent::TorrentHandle *const, const QString &>(&TransferListFiltersWidget::trackerSuccess));
+        , m_transferListFiltersWidget, qOverload<const BitTorrent::TorrentHandle *, const QString &>(&TransferListFiltersWidget::trackerSuccess));
     connect(BitTorrent::Session::instance(), &BitTorrent::Session::trackerError
-        , m_transferListFiltersWidget, qOverload<BitTorrent::TorrentHandle *const, const QString &>(&TransferListFiltersWidget::trackerError));
+        , m_transferListFiltersWidget, qOverload<const BitTorrent::TorrentHandle *, const QString &>(&TransferListFiltersWidget::trackerError));
     connect(BitTorrent::Session::instance(), &BitTorrent::Session::trackerWarning
-        , m_transferListFiltersWidget, qOverload<BitTorrent::TorrentHandle *const, const QString &>(&TransferListFiltersWidget::trackerWarning));
+        , m_transferListFiltersWidget, qOverload<const BitTorrent::TorrentHandle *, const QString &>(&TransferListFiltersWidget::trackerWarning));
 
 #ifdef Q_OS_MACOS
     // Increase top spacing to avoid tab overlapping
diff --git a/src/gui/transferlistfilterswidget.cpp b/src/gui/transferlistfilterswidget.cpp
index ed79b251ed7..53788b48577 100644
--- a/src/gui/transferlistfilterswidget.cpp
+++ b/src/gui/transferlistfilterswidget.cpp
@@ -74,6 +74,19 @@ namespace
         return scheme;
     }
 
+    QString getHost(const QString &tracker)
+    {
+        // We want the domain + tld. Subdomains should be disregarded
+        const QUrl url {tracker};
+        const QString host {url.host()};
+
+        // host is in IP format
+        if (!QHostAddress(host).isNull())
+            return host;
+
+        return host.section('.', -2, -1);
+    }
+
     class ArrowCheckBox final : public QCheckBox
     {
     public:
@@ -97,6 +110,8 @@ namespace
             style()->drawControl(QStyle::CE_CheckBoxLabel, &labelOption, &painter, this);
         }
     };
+
+    const QString NULL_HOST {""};
 }
 
 BaseFilterWidget::BaseFilterWidget(QWidget *parent, TransferListWidget *transferList)
@@ -294,7 +309,7 @@ TrackerFiltersList::TrackerFiltersList(QWidget *parent, TransferListWidget *tran
     auto *warningTracker = new QListWidgetItem(this);
     warningTracker->setData(Qt::DisplayRole, tr("Warning (0)"));
     warningTracker->setData(Qt::DecorationRole, style()->standardIcon(QStyle::SP_MessageBoxWarning));
-    m_trackers.insert("", QStringList());
+    m_trackers[NULL_HOST] = {};
 
     setCurrentRow(0, QItemSelectionModel::SelectCurrent);
     toggleFilter(Preferences::instance()->getTrackerFilterState());
@@ -306,27 +321,20 @@ TrackerFiltersList::~TrackerFiltersList()
         Utils::Fs::forceRemove(iconPath);
 }
 
-void TrackerFiltersList::addItem(const QString &tracker, const QString &hash)
+void TrackerFiltersList::addItem(const QString &tracker, const BitTorrent::InfoHash &hash)
 {
-    QStringList tmp;
-    QListWidgetItem *trackerItem = nullptr;
-    QString host = getHost(tracker);
-    bool exists = m_trackers.contains(host);
+    const QString host {getHost(tracker)};
+    const bool exists {m_trackers.contains(host)};
+    QListWidgetItem *trackerItem {nullptr};
 
     if (exists)
     {
-        tmp = m_trackers.value(host);
-        if (tmp.contains(hash))
+        if (m_trackers.value(host).contains(hash))
             return;
 
-        if (host != "")
-        {
-            trackerItem = item(rowFromTracker(host));
-        }
-        else
-        {
-            trackerItem = item(TRACKERLESS_ROW);
-        }
+        trackerItem = item((host == NULL_HOST)
+            ? TRACKERLESS_ROW
+            : rowFromTracker(host));
     }
     else
     {
@@ -338,17 +346,18 @@ void TrackerFiltersList::addItem(const QString &tracker, const QString &hash)
     }
     if (!trackerItem) return;
 
-    tmp.append(hash);
-    m_trackers.insert(host, tmp);
-    if (host == "")
+    QSet<BitTorrent::InfoHash> &hashes {m_trackers[host]};
+    hashes.insert(hash);
+
+    if (host == NULL_HOST)
     {
-        trackerItem->setText(tr("Trackerless (%1)").arg(tmp.size()));
+        trackerItem->setText(tr("Trackerless (%1)").arg(hashes.size()));
         if (currentRow() == TRACKERLESS_ROW)
             applyFilter(TRACKERLESS_ROW);
         return;
     }
 
-    trackerItem->setText(QString::fromLatin1("%1 (%2)").arg(host, QString::number(tmp.size())));
+    trackerItem->setText(QString::fromLatin1("%1 (%2)").arg(host, QString::number(hashes.size())));
     if (exists)
     {
         if (currentRow() == rowFromTracker(host))
@@ -370,16 +379,17 @@ void TrackerFiltersList::addItem(const QString &tracker, const QString &hash)
     updateGeometry();
 }
 
-void TrackerFiltersList::removeItem(const QString &tracker, const QString &hash)
+void TrackerFiltersList::removeItem(const QString &tracker, const BitTorrent::InfoHash &hash)
 {
-    QString host = getHost(tracker);
-    QListWidgetItem *trackerItem = nullptr;
-    QStringList tmp = m_trackers.value(host);
-    int row = 0;
+    const QString host = getHost(tracker);
+    QSet<BitTorrent::InfoHash> hashes = m_trackers.value(host);
 
-    if (tmp.empty())
+    if (hashes.empty())
         return;
-    tmp.removeAll(hash);
+    hashes.remove(hash);
+
+    int row = 0;
+    QListWidgetItem *trackerItem = nullptr;
 
     if (!host.isEmpty())
     {
@@ -387,7 +397,8 @@ void TrackerFiltersList::removeItem(const QString &tracker, const QString &hash)
         trackerSuccess(hash, tracker);
         row = rowFromTracker(host);
         trackerItem = item(row);
-        if (tmp.empty())
+
+        if (hashes.empty())
         {
             if (currentRow() == row)
                 setCurrentRow(0, QItemSelectionModel::SelectCurrent);
@@ -396,27 +407,29 @@ void TrackerFiltersList::removeItem(const QString &tracker, const QString &hash)
             updateGeometry();
             return;
         }
+
         if (trackerItem)
-            trackerItem->setText(QString::fromLatin1("%1 (%2)").arg(host, QString::number(tmp.size())));
+            trackerItem->setText(QString::fromLatin1("%1 (%2)").arg(host, QString::number(hashes.size())));
     }
     else
     {
         row = 1;
         trackerItem = item(TRACKERLESS_ROW);
-        trackerItem->setText(tr("Trackerless (%1)").arg(tmp.size()));
+        trackerItem->setText(tr("Trackerless (%1)").arg(hashes.size()));
     }
 
-    m_trackers.insert(host, tmp);
+    m_trackers.insert(host, hashes);
+
     if (currentRow() == row)
         applyFilter(row);
 }
 
-void TrackerFiltersList::changeTrackerless(bool trackerless, const QString &hash)
+void TrackerFiltersList::changeTrackerless(const bool trackerless, const BitTorrent::InfoHash &hash)
 {
     if (trackerless)
-        addItem("", hash);
+        addItem(NULL_HOST, hash);
     else
-        removeItem("", hash);
+        removeItem(NULL_HOST, hash);
 }
 
 void TrackerFiltersList::setDownloadTrackerFavicon(bool value)
@@ -439,70 +452,57 @@ void TrackerFiltersList::setDownloadTrackerFavicon(bool value)
     }
 }
 
-void TrackerFiltersList::trackerSuccess(const QString &hash, const QString &tracker)
+void TrackerFiltersList::trackerSuccess(const BitTorrent::InfoHash &hash, const QString &tracker)
 {
-    QStringList errored = m_errors.value(hash);
-    QStringList warned = m_warnings.value(hash);
-
-    if (errored.contains(tracker))
+    const auto errorHashesIter = m_errors.find(hash);
+    if (errorHashesIter != m_errors.end())
     {
-        errored.removeAll(tracker);
+        QSet<QString> &errored = *errorHashesIter;
+        errored.remove(tracker);
         if (errored.empty())
         {
-            m_errors.remove(hash);
+            m_errors.erase(errorHashesIter);
             item(ERROR_ROW)->setText(tr("Error (%1)").arg(m_errors.size()));
             if (currentRow() == ERROR_ROW)
                 applyFilter(ERROR_ROW);
         }
-        else
-        {
-            m_errors.insert(hash, errored);
-        }
     }
 
-    if (warned.contains(tracker))
+    const auto warningHashesIter = m_warnings.find(hash);
+    if (warningHashesIter != m_warnings.end())
     {
-        warned.removeAll(tracker);
+        QSet<QString> &warned = *warningHashesIter;
+        warned.remove(tracker);
         if (warned.empty())
         {
-            m_warnings.remove(hash);
+            m_warnings.erase(warningHashesIter);
             item(WARNING_ROW)->setText(tr("Warning (%1)").arg(m_warnings.size()));
             if (currentRow() == WARNING_ROW)
                 applyFilter(WARNING_ROW);
         }
-        else
-        {
-            m_warnings.insert(hash, warned);
-        }
     }
 }
 
-void TrackerFiltersList::trackerError(const QString &hash, const QString &tracker)
+void TrackerFiltersList::trackerError(const BitTorrent::InfoHash &hash, const QString &tracker)
 {
-    QStringList trackers = m_errors.value(hash);
-
+    QSet<QString> &trackers {m_errors[hash]};
     if (trackers.contains(tracker))
         return;
 
-    trackers.append(tracker);
-    m_errors.insert(hash, trackers);
+    trackers.insert(tracker);
     item(ERROR_ROW)->setText(tr("Error (%1)").arg(m_errors.size()));
-
     if (currentRow() == ERROR_ROW)
         applyFilter(ERROR_ROW);
 }
 
-void TrackerFiltersList::trackerWarning(const QString &hash, const QString &tracker)
+void TrackerFiltersList::trackerWarning(const BitTorrent::InfoHash &hash, const QString &tracker)
 {
-    QStringList trackers = m_warnings.value(hash);
-
+    QSet<QString> &trackers {m_warnings[hash]};
     if (trackers.contains(tracker))
         return;
 
-    trackers.append(tracker);
-    m_warnings.insert(hash, trackers);
+    trackers.insert(tracker);
     item(WARNING_ROW)->setText(tr("Warning (%1)").arg(m_warnings.size()));
-
     if (currentRow() == WARNING_ROW)
         applyFilter(WARNING_ROW);
 }
@@ -574,33 +574,33 @@ void TrackerFiltersList::applyFilter(const int row)
     if (row == ALL_ROW)
         transferList->applyTrackerFilterAll();
     else if (isVisible())
-        transferList->applyTrackerFilter(getHashes(row));
+        transferList->applyTrackerFilter(getInfoHashes(row));
 }
 
 void TrackerFiltersList::handleNewTorrent(BitTorrent::TorrentHandle *const torrent)
 {
-    QString hash = torrent->hash();
-    const QVector<BitTorrent::TrackerEntry> trackers = torrent->trackers();
+    const BitTorrent::InfoHash hash {torrent->hash()};
+    const QVector<BitTorrent::TrackerEntry> trackers {torrent->trackers()};
     for (const BitTorrent::TrackerEntry &tracker : trackers)
         addItem(tracker.url(), hash);
 
-    //Check for trackerless torrent
+    // Check for trackerless torrent
     if (trackers.isEmpty())
-        addItem("", hash);
+        addItem(NULL_HOST, hash);
 
     item(ALL_ROW)->setText(tr("All (%1)", "this is for the tracker filter").arg(++m_totalTorrents));
 }
 
 void TrackerFiltersList::torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const torrent)
 {
-    QString hash = torrent->hash();
-    const QVector<BitTorrent::TrackerEntry> trackers = torrent->trackers();
+    const BitTorrent::InfoHash hash {torrent->hash()};
+    const QVector<BitTorrent::TrackerEntry> trackers {torrent->trackers()};
     for (const BitTorrent::TrackerEntry &tracker : trackers)
         removeItem(tracker.url(), hash);
 
-    //Check for trackerless torrent
+    // Check for trackerless torrent
     if (trackers.isEmpty())
-        removeItem("", hash);
+        removeItem(NULL_HOST, hash);
 
     item(ALL_ROW)->setText(tr("All (%1)", "this is for the tracker filter").arg(--m_totalTorrents));
 }
@@ -618,34 +618,24 @@ QString TrackerFiltersList::trackerFromRow(int row) const
 int TrackerFiltersList::rowFromTracker(const QString &tracker) const
 {
     Q_ASSERT(!tracker.isEmpty());
-    for (int i = 4; i<count(); ++i)
-        if (tracker == trackerFromRow(i)) return i;
+    for (int i = 4; i < count(); ++i)
+    {
+        if (tracker == trackerFromRow(i))
+            return i;
+    }
     return -1;
 }
 
-QString TrackerFiltersList::getHost(const QString &tracker) const
-{
-    // We want the domain + tld. Subdomains should be disregarded
-    const QUrl url {tracker};
-    const QString host {url.host()};
-
-    // host is in IP format
-    if (!QHostAddress(host).isNull())
-        return host;
-
-    return host.section('.', -2, -1);
-}
-
-QStringList TrackerFiltersList::getHashes(const int row) const
+QSet<BitTorrent::InfoHash> TrackerFiltersList::getInfoHashes(const int row) const
 {
     switch (row)
     {
     case TRACKERLESS_ROW:
-        return m_trackers.value("");
+        return m_trackers.value(NULL_HOST);
     case ERROR_ROW:
-        return m_errors.keys();
+        return List::toSet(m_errors.keys());
     case WARNING_ROW:
-        return m_warnings.keys();
+        return List::toSet(m_warnings.keys());
     default:
         return m_trackers.value(trackerFromRow(row));
     }
@@ -739,11 +729,11 @@ TransferListFiltersWidget::TransferListFiltersWidget(QWidget *parent, TransferLi
     connect(trackerLabel, &QCheckBox::toggled, m_trackerFilters, &TrackerFiltersList::toggleFilter);
     connect(trackerLabel, &QCheckBox::toggled, pref, &Preferences::setTrackerFilterState);
 
-    connect(this, qOverload<const QString &, const QString &>(&TransferListFiltersWidget::trackerSuccess)
+    connect(this, qOverload<const BitTorrent::InfoHash &, const QString &>(&TransferListFiltersWidget::trackerSuccess)
             , m_trackerFilters, &TrackerFiltersList::trackerSuccess);
-    connect(this, qOverload<const QString &, const QString &>(&TransferListFiltersWidget::trackerError)
+    connect(this, qOverload<const BitTorrent::InfoHash &, const QString &>(&TransferListFiltersWidget::trackerError)
             , m_trackerFilters, &TrackerFiltersList::trackerError);
-    connect(this, qOverload<const QString &, const QString &>(&TransferListFiltersWidget::trackerWarning)
+    connect(this, qOverload<const BitTorrent::InfoHash &, const QString &>(&TransferListFiltersWidget::trackerWarning)
             , m_trackerFilters, &TrackerFiltersList::trackerWarning);
 }
 
@@ -752,34 +742,34 @@ void TransferListFiltersWidget::setDownloadTrackerFavicon(bool value)
     m_trackerFilters->setDownloadTrackerFavicon(value);
 }
 
-void TransferListFiltersWidget::addTrackers(BitTorrent::TorrentHandle *const torrent, const QVector<BitTorrent::TrackerEntry> &trackers)
+void TransferListFiltersWidget::addTrackers(const BitTorrent::TorrentHandle *torrent, const QVector<BitTorrent::TrackerEntry> &trackers)
 {
     for (const BitTorrent::TrackerEntry &tracker : trackers)
         m_trackerFilters->addItem(tracker.url(), torrent->hash());
 }
 
-void TransferListFiltersWidget::removeTrackers(BitTorrent::TorrentHandle *const torrent, const QVector<BitTorrent::TrackerEntry> &trackers)
+void TransferListFiltersWidget::removeTrackers(const BitTorrent::TorrentHandle *torrent, const QVector<BitTorrent::TrackerEntry> &trackers)
 {
     for (const BitTorrent::TrackerEntry &tracker : trackers)
         m_trackerFilters->removeItem(tracker.url(), torrent->hash());
 }
 
-void TransferListFiltersWidget::changeTrackerless(BitTorrent::TorrentHandle *const torrent, bool trackerless)
+void TransferListFiltersWidget::changeTrackerless(const BitTorrent::TorrentHandle *torrent, const bool trackerless)
 {
     m_trackerFilters->changeTrackerless(trackerless, torrent->hash());
 }
 
-void TransferListFiltersWidget::trackerSuccess(BitTorrent::TorrentHandle *const torrent, const QString &tracker)
+void TransferListFiltersWidget::trackerSuccess(const BitTorrent::TorrentHandle *torrent, const QString &tracker)
 {
     emit trackerSuccess(torrent->hash(), tracker);
 }
 
-void TransferListFiltersWidget::trackerWarning(BitTorrent::TorrentHandle *const torrent, const QString &tracker)
+void TransferListFiltersWidget::trackerWarning(const BitTorrent::TorrentHandle *torrent, const QString &tracker)
 {
     emit trackerWarning(torrent->hash(), tracker);
 }
 
-void TransferListFiltersWidget::trackerError(BitTorrent::TorrentHandle *const torrent, const QString &tracker)
+void TransferListFiltersWidget::trackerError(const BitTorrent::TorrentHandle *torrent, const QString &tracker)
 {
     emit trackerError(torrent->hash(), tracker);
 }
diff --git a/src/gui/transferlistfilterswidget.h b/src/gui/transferlistfilterswidget.h
index 3b03189894c..ed6b01d0a63 100644
--- a/src/gui/transferlistfilterswidget.h
+++ b/src/gui/transferlistfilterswidget.h
@@ -31,6 +31,7 @@
 
 #include <QFrame>
 #include <QListWidget>
+#include <QtContainerFwd>
 
 class QCheckBox;
 class QResizeEvent;
@@ -39,6 +40,7 @@ class TransferListWidget;
 
 namespace BitTorrent
 {
+    class InfoHash;
     class TorrentHandle;
     class TrackerEntry;
 }
@@ -103,15 +105,15 @@ class TrackerFiltersList final : public BaseFilterWidget
     ~TrackerFiltersList() override;
 
     // Redefine addItem() to make sure the list stays sorted
-    void addItem(const QString &tracker, const QString &hash);
-    void removeItem(const QString &tracker, const QString &hash);
-    void changeTrackerless(bool trackerless, const QString &hash);
+    void addItem(const QString &tracker, const BitTorrent::InfoHash &hash);
+    void removeItem(const QString &tracker, const BitTorrent::InfoHash &hash);
+    void changeTrackerless(bool trackerless, const BitTorrent::InfoHash &hash);
     void setDownloadTrackerFavicon(bool value);
 
 public slots:
-    void trackerSuccess(const QString &hash, const QString &tracker);
-    void trackerError(const QString &hash, const QString &tracker);
-    void trackerWarning(const QString &hash, const QString &tracker);
+    void trackerSuccess(const BitTorrent::InfoHash &hash, const QString &tracker);
+    void trackerError(const BitTorrent::InfoHash &hash, const QString &tracker);
+    void trackerWarning(const BitTorrent::InfoHash &hash, const QString &tracker);
 
 private slots:
     void handleFavicoDownloadFinished(const Net::DownloadResult &result);
@@ -125,13 +127,12 @@ private slots:
     void torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const torrent) override;
     QString trackerFromRow(int row) const;
     int rowFromTracker(const QString &tracker) const;
-    QString getHost(const QString &tracker) const;
-    QStringList getHashes(int row) const;
+    QSet<BitTorrent::InfoHash> getInfoHashes(int row) const;
     void downloadFavicon(const QString &url);
 
-    QHash<QString, QStringList> m_trackers;
-    QHash<QString, QStringList> m_errors;
-    QHash<QString, QStringList> m_warnings;
+    QHash<QString, QSet<BitTorrent::InfoHash>> m_trackers;  // <tracker host, torrent hashes>
+    QHash<BitTorrent::InfoHash, QSet<QString>> m_errors;  // <torrent hash, tracker hosts>
+    QHash<BitTorrent::InfoHash, QSet<QString>> m_warnings;  // <torrent hash, tracker hosts>
     QStringList m_iconPaths;
     int m_totalTorrents;
     bool m_downloadTrackerFavicon;
@@ -140,26 +141,27 @@ private slots:
 class CategoryFilterWidget;
 class TagFilterWidget;
 
-class TransferListFiltersWidget : public QFrame
+class TransferListFiltersWidget final : public QFrame
 {
     Q_OBJECT
+    Q_DISABLE_COPY(TransferListFiltersWidget)
 
 public:
     TransferListFiltersWidget(QWidget *parent, TransferListWidget *transferList, bool downloadFavicon);
     void setDownloadTrackerFavicon(bool value);
 
 public slots:
-    void addTrackers(BitTorrent::TorrentHandle *const torrent, const QVector<BitTorrent::TrackerEntry> &trackers);
-    void removeTrackers(BitTorrent::TorrentHandle *const torrent, const QVector<BitTorrent::TrackerEntry> &trackers);
-    void changeTrackerless(BitTorrent::TorrentHandle *const torrent, bool trackerless);
-    void trackerSuccess(BitTorrent::TorrentHandle *const torrent, const QString &tracker);
-    void trackerWarning(BitTorrent::TorrentHandle *const torrent, const QString &tracker);
-    void trackerError(BitTorrent::TorrentHandle *const torrent, const QString &tracker);
+    void addTrackers(const BitTorrent::TorrentHandle *torrent, const QVector<BitTorrent::TrackerEntry> &trackers);
+    void removeTrackers(const BitTorrent::TorrentHandle *torrent, const QVector<BitTorrent::TrackerEntry> &trackers);
+    void changeTrackerless(const BitTorrent::TorrentHandle *torrent, bool trackerless);
+    void trackerSuccess(const BitTorrent::TorrentHandle *torrent, const QString &tracker);
+    void trackerWarning(const BitTorrent::TorrentHandle *torrent, const QString &tracker);
+    void trackerError(const BitTorrent::TorrentHandle *torrent, const QString &tracker);
 
 signals:
-    void trackerSuccess(const QString &hash, const QString &tracker);
-    void trackerError(const QString &hash, const QString &tracker);
-    void trackerWarning(const QString &hash, const QString &tracker);
+    void trackerSuccess(const BitTorrent::InfoHash &hash, const QString &tracker);
+    void trackerError(const BitTorrent::InfoHash &hash, const QString &tracker);
+    void trackerWarning(const BitTorrent::InfoHash &hash, const QString &tracker);
 
 private slots:
     void onCategoryFilterStateChanged(bool enabled);
diff --git a/src/gui/transferlistsortmodel.cpp b/src/gui/transferlistsortmodel.cpp
index 4177eb32559..310dc0d7806 100644
--- a/src/gui/transferlistsortmodel.cpp
+++ b/src/gui/transferlistsortmodel.cpp
@@ -29,7 +29,6 @@
 #include "transferlistsortmodel.h"
 
 #include <QDateTime>
-#include <QStringList>
 
 #include "base/bittorrent/infohash.h"
 #include "base/bittorrent/torrenthandle.h"
@@ -75,9 +74,9 @@ void TransferListSortModel::disableTagFilter()
         invalidateFilter();
 }
 
-void TransferListSortModel::setTrackerFilter(const QStringList &hashes)
+void TransferListSortModel::setTrackerFilter(const QSet<BitTorrent::InfoHash> &hashes)
 {
-    if (m_filter.setHashSet(List::toSet(hashes)))
+    if (m_filter.setHashSet(hashes))
         invalidateFilter();
 }
 
diff --git a/src/gui/transferlistsortmodel.h b/src/gui/transferlistsortmodel.h
index b8ea1336e85..b63206bbe77 100644
--- a/src/gui/transferlistsortmodel.h
+++ b/src/gui/transferlistsortmodel.h
@@ -31,7 +31,10 @@
 #include <QSortFilterProxyModel>
 #include "base/torrentfilter.h"
 
-class QStringList;
+namespace BitTorrent
+{
+    class InfoHash;
+}
 
 class TransferListSortModel final : public QSortFilterProxyModel
 {
@@ -46,7 +49,7 @@ class TransferListSortModel final : public QSortFilterProxyModel
     void disableCategoryFilter();
     void setTagFilter(const QString &tag);
     void disableTagFilter();
-    void setTrackerFilter(const QStringList &hashes);
+    void setTrackerFilter(const QSet<BitTorrent::InfoHash> &hashes);
     void disableTrackerFilter();
 
 private:
diff --git a/src/gui/transferlistwidget.cpp b/src/gui/transferlistwidget.cpp
index 91892600f53..4e17233cb1a 100644
--- a/src/gui/transferlistwidget.cpp
+++ b/src/gui/transferlistwidget.cpp
@@ -41,6 +41,7 @@
 #include <QSet>
 #include <QShortcut>
 #include <QTableView>
+#include <QVector>
 #include <QWheelEvent>
 
 #include "base/bittorrent/infohash.h"
@@ -1226,7 +1227,7 @@ void TransferListWidget::applyTrackerFilterAll()
     m_sortFilterModel->disableTrackerFilter();
 }
 
-void TransferListWidget::applyTrackerFilter(const QStringList &hashes)
+void TransferListWidget::applyTrackerFilter(const QSet<BitTorrent::InfoHash> &hashes)
 {
     m_sortFilterModel->setTrackerFilter(hashes);
 }
diff --git a/src/gui/transferlistwidget.h b/src/gui/transferlistwidget.h
index 4282fa46835..1c47cb7b50b 100644
--- a/src/gui/transferlistwidget.h
+++ b/src/gui/transferlistwidget.h
@@ -30,8 +30,8 @@
 #define TRANSFERLISTWIDGET_H
 
 #include <functional>
+#include <QtContainerFwd>
 #include <QTreeView>
-#include <QVector>
 
 class MainWindow;
 class TransferListDelegate;
@@ -40,6 +40,7 @@ class TransferListSortModel;
 
 namespace BitTorrent
 {
+    class InfoHash;
     class TorrentHandle;
 }
 
@@ -90,7 +91,7 @@ public slots:
     void applyCategoryFilter(const QString &category);
     void applyTagFilter(const QString &tag);
     void applyTrackerFilterAll();
-    void applyTrackerFilter(const QStringList &hashes);
+    void applyTrackerFilter(const QSet<BitTorrent::InfoHash> &hashes);
     void previewFile(const QString &filePath);
     void renameSelectedTorrent();
 
diff --git a/src/webui/api/torrentscontroller.cpp b/src/webui/api/torrentscontroller.cpp
index 28fe6ab03b9..71b2c13da7a 100644
--- a/src/webui/api/torrentscontroller.cpp
+++ b/src/webui/api/torrentscontroller.cpp
@@ -256,10 +256,14 @@ void TorrentsController::infoAction()
     const bool reverse {parseBool(params()["reverse"], false)};
     int limit {params()["limit"].toInt()};
     int offset {params()["offset"].toInt()};
-    const QStringSet hashSet {List::toSet(params()["hashes"].split('|', QString::SkipEmptyParts))};
+    const QStringList hashes {params()["hashes"].split('|', QString::SkipEmptyParts)};
+
+    InfoHashSet hashSet;
+    for (const QString &hash : hashes)
+        hashSet.insert(BitTorrent::InfoHash {hash});
 
     QVariantList torrentList;
-    TorrentFilter torrentFilter(filter, (hashSet.isEmpty() ? TorrentFilter::AnyHash : hashSet), category);
+    TorrentFilter torrentFilter(filter, (hashes.isEmpty() ? TorrentFilter::AnyHash : hashSet), category);
     for (BitTorrent::TorrentHandle *const torrent : asConst(BitTorrent::Session::instance()->torrents()))
     {
         if (torrentFilter.match(torrent))