diff --git a/qt/DetailsDialog.cc b/qt/DetailsDialog.cc
index 33f71e6b5af..4a2159c7772 100644
--- a/qt/DetailsDialog.cc
+++ b/qt/DetailsDialog.cc
@@ -21,7 +21,6 @@
 #include <QItemSelectionModel>
 #include <QLabel>
 #include <QList>
-#include <QMap>
 #include <QMessageBox>
 #include <QResizeEvent>
 #include <QRegularExpression>
@@ -1098,20 +1097,23 @@ void DetailsDialog::refreshUI()
     ///  Peers tab
     ///
 
-    QMap<QString, QTreeWidgetItem*> peers2;
+    auto peers2 = decltype(peers_){};
     QList<QTreeWidgetItem*> new_items;
 
     for (Torrent const* const t : torrents)
     {
         QString const id_str(QString::number(t->id()));
-        PeerList const peers = t->peers();
 
-        for (Peer const& peer : peers)
+        for (Peer const& peer : t->peers())
         {
             QString const key = id_str + QLatin1Char(':') + peer.address;
-            auto* item = dynamic_cast<PeerItem*>(peers_.value(key, nullptr));
 
-            if (item == nullptr) // new peer has connected
+            PeerItem* item = nullptr;
+            if (auto iter = peers_.find(key); iter != std::end(peers_))
+            {
+                item = dynamic_cast<PeerItem*>(iter->second);
+            }
+            else // new peer has connected
             {
                 item = new PeerItem(peer);
                 item->setTextAlignment(COL_UP, Qt::AlignRight | Qt::AlignVCenter);
@@ -1124,7 +1126,7 @@ void DetailsDialog::refreshUI()
                 new_items << item;
             }
 
-            QString const code = peer.flags;
+            auto const& code = peer.flags;
             item->setStatus(code);
             item->refresh(peer);
 
@@ -1207,23 +1209,22 @@ void DetailsDialog::refreshUI()
             item->setText(COL_STATUS, code);
             item->setToolTip(COL_STATUS, code_tip);
 
-            peers2.insert(key, item);
+            peers2.try_emplace(key, item);
         }
     }
 
     ui_.peersView->addTopLevelItems(new_items);
 
-    for (QString const& key : peers_.keys())
+    for (auto const& [key, item] : peers_)
     {
-        if (!peers2.contains(key)) // old peer has disconnected
+        if (peers2.count(key) == 0U) // old peer has disconnected
         {
-            QTreeWidgetItem* item = peers_.value(key, nullptr);
             ui_.peersView->takeTopLevelItem(ui_.peersView->indexOfTopLevelItem(item));
             delete item;
         }
     }
 
-    peers_ = peers2;
+    peers_ = std::move(peers2);
 
     if (single)
     {
diff --git a/qt/DetailsDialog.h b/qt/DetailsDialog.h
index 7c84b0aab2e..aa64d08e3c7 100644
--- a/qt/DetailsDialog.h
+++ b/qt/DetailsDialog.h
@@ -5,11 +5,11 @@
 
 #pragma once
 
+#include <map>
 #include <memory>
 #include <unordered_set>
 
 #include <QString>
-#include <QMap>
 #include <QSet>
 #include <QTimer>
 
@@ -137,7 +137,7 @@ private slots:
     std::shared_ptr<TrackerModelFilter> tracker_filter_;
     std::shared_ptr<TrackerDelegate> tracker_delegate_;
 
-    QMap<QString, QTreeWidgetItem*> peers_;
+    std::map<QString, QTreeWidgetItem*> peers_;
 
     QIcon const icon_encrypted_ = QIcon(QStringLiteral(":/icons/encrypted.svg"));
     QIcon const icon_unencrypted_ = {};
diff --git a/qt/FileTreeModel.cc b/qt/FileTreeModel.cc
index 0f55c7626cb..821ce9b34f0 100644
--- a/qt/FileTreeModel.cc
+++ b/qt/FileTreeModel.cc
@@ -5,6 +5,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <map>
 #include <memory>
 
 #include <libtransmission/transmission.h> // priorities
@@ -463,7 +464,7 @@ void FileTreeModel::emitSubtreeChanged(QModelIndex const& idx, int first_column,
 
 void FileTreeModel::twiddleWanted(QModelIndexList const& indices)
 {
-    QMap<bool, QModelIndexList> wanted_indices;
+    std::map<bool, QModelIndexList> wanted_indices;
 
     for (QModelIndex const& i : getOrphanIndices(indices))
     {
@@ -473,7 +474,7 @@ void FileTreeModel::twiddleWanted(QModelIndexList const& indices)
 
     for (int i = 0; i <= 1; ++i)
     {
-        if (wanted_indices.contains(i))
+        if (wanted_indices.count(i) != 0)
         {
             setWanted(wanted_indices[i], i != 0);
         }
@@ -482,7 +483,7 @@ void FileTreeModel::twiddleWanted(QModelIndexList const& indices)
 
 void FileTreeModel::twiddlePriority(QModelIndexList const& indices)
 {
-    QMap<int, QModelIndexList> priority_indices;
+    std::map<int, QModelIndexList> priority_indices;
 
     for (QModelIndex const& i : getOrphanIndices(indices))
     {
@@ -508,7 +509,7 @@ void FileTreeModel::twiddlePriority(QModelIndexList const& indices)
 
     for (int i = TR_PRI_LOW; i <= TR_PRI_HIGH; ++i)
     {
-        if (priority_indices.contains(i))
+        if (priority_indices.count(i) != 0U)
         {
             setPriority(priority_indices[i], i);
         }
diff --git a/qt/OptionsDialog.h b/qt/OptionsDialog.h
index d14961240fa..342ce3aa400 100644
--- a/qt/OptionsDialog.h
+++ b/qt/OptionsDialog.h
@@ -5,12 +5,12 @@
 
 #pragma once
 
+#include <map>
 #include <optional>
 #include <vector>
 
 #include <QDir>
 #include <QFile>
-#include <QMap>
 #include <QSet>
 #include <QString>
 #include <QTimer>
@@ -54,7 +54,7 @@ private slots:
     void onSessionUpdated();
 
 private:
-    using mybins_t = QMap<uint32_t, int32_t>;
+    using mybins_t = std::map<uint32_t, int32_t>;
 
     void reload();
     void updateWidgetsLocality();
diff --git a/qt/PrefsDialog.cc b/qt/PrefsDialog.cc
index 996b4c78ec0..ea33bec762b 100644
--- a/qt/PrefsDialog.cc
+++ b/qt/PrefsDialog.cc
@@ -203,7 +203,7 @@ void PrefsDialog::linkWidgetToPref(QWidget* widget, int pref_key)
 
     pref_widget.setPrefKey(pref_key);
     updateWidgetValue(widget, pref_key);
-    widgets_.insert(pref_key, widget);
+    widgets_.try_emplace(pref_key, widget);
 
     if (auto const* check_box = qobject_cast<QCheckBox*>(widget); check_box != nullptr)
     {
@@ -807,11 +807,9 @@ void PrefsDialog::refreshPref(int key)
         break;
     }
 
-    key2widget_t::iterator const it(widgets_.find(key));
-
-    if (it != widgets_.end())
+    if (auto iter = widgets_.find(key); iter != std::end(widgets_))
     {
-        QWidget* w(it.value());
+        QWidget* const w = iter->second;
 
         w->blockSignals(true);
 
diff --git a/qt/PrefsDialog.h b/qt/PrefsDialog.h
index 8d8abe89af7..405d595c177 100644
--- a/qt/PrefsDialog.h
+++ b/qt/PrefsDialog.h
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <QMap>
+#include <map>
 
 #include <libtransmission/tr-macros.h>
 
@@ -50,7 +50,7 @@ private slots:
     void onBlocklistUpdated(int n);
 
 private:
-    using key2widget_t = QMap<int, QWidget*>;
+    using key2widget_t = std::map<int, QWidget*>;
 
     bool updateWidgetValue(QWidget* widget, int pref_key) const;
     void linkWidgetToPref(QWidget* widget, int pref_key);