diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3ee966f42..7e1ca311c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,7 +53,7 @@ set(OPENSSL_MINIMUM 1.1.0)
 set(MBEDTLS_MINIMUM 2.7)
 set(NPM_MINIMUM 10.2.3) # Node.js 20.10 (eslint-plugin-unicorn)
 set(PSL_MINIMUM 0.21.1)
-set(QT_MINIMUM 5.6)
+set(QT_MINIMUM 5.15)
 
 option(ENABLE_DAEMON "Build daemon" ON)
 tr_auto_option(ENABLE_GTK "Build GTK client" AUTO)
diff --git a/qt/DetailsDialog.cc b/qt/DetailsDialog.cc
index 7f4fb06d9..e654923d0 100644
--- a/qt/DetailsDialog.cc
+++ b/qt/DetailsDialog.cc
@@ -414,12 +414,8 @@ void DetailsDialog::onButtonBoxClicked(QAbstractButton* button)
 
         QString const re = QStringLiteral("((,|;)\\s*)");
 
-//see https://doc.qt.io/qt-5/qt.html#SplitBehaviorFlags-enum
-#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
-        QStringList const labels_list = labels_text.split(QRegularExpression(re), QString::SkipEmptyParts);
-#else
+        // see https://doc.qt.io/qt-5/qt.html#SplitBehaviorFlags-enum
         QStringList const labels_list = labels_text.split(QRegularExpression(re), Qt::SkipEmptyParts);
-#endif
 
         torrentSet(TR_KEY_labels, labels_list);
 
diff --git a/qt/Prefs.cc b/qt/Prefs.cc
index 5248bc5b2..1e72abb3e 100644
--- a/qt/Prefs.cc
+++ b/qt/Prefs.cc
@@ -313,11 +313,7 @@ Prefs::Prefs(QString config_dir)
         case QMetaType::QDateTime:
             if (auto const value = getValue<time_t>(b); value)
             {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
                 values_[i].setValue(QDateTime::fromSecsSinceEpoch(*value));
-#else
-                values_[i].setValue(QDateTime::fromTime_t(*value));
-#endif
             }
             break;
 
@@ -395,11 +391,7 @@ Prefs::~Prefs()
             break;
 
         case QMetaType::QDateTime:
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
             dictAdd(&current_settings, key, int64_t{ val.toDateTime().toSecsSinceEpoch() });
-#else
-            dictAdd(&current_settings, key, val.toDateTime().toTime_t());
-#endif
             break;
 
         default:
diff --git a/qt/Utils.h b/qt/Utils.h
index 5345ec069..32b1056cd 100644
--- a/qt/Utils.h
+++ b/qt/Utils.h
@@ -5,7 +5,6 @@
 
 #pragma once
 
-#include <cstddef> // size_t
 #include <utility>
 
 #include <QPointer>
@@ -19,24 +18,6 @@ class QHeaderView;
 class QIcon;
 class QModelIndex;
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
-
-namespace std
-{
-
-template<>
-struct hash<QString>
-{
-    std::size_t operator()(QString const& s) const
-    {
-        return qHash(s);
-    }
-};
-
-} // namespace std
-
-#endif
-
 class Utils
 {
 public: