diff --git a/src/libs/utils/algorithm.h b/src/libs/utils/algorithm.h
index 32ad6d3e46f..a5b29db0878 100644
--- a/src/libs/utils/algorithm.h
+++ b/src/libs/utils/algorithm.h
@@ -1296,14 +1296,6 @@ QSet<T> toSet(const QList<T> &list)
     return QSet<T>(list.begin(), list.end());
 }
 
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-template<class T>
-QSet<T> toSet(const QVector<T> &vec)
-{
-    return QSet<T>(vec.begin(), vec.end());
-}
-#endif
-
 template<class T>
 QList<T> toList(const QSet<T> &set)
 {
diff --git a/src/libs/utils/launcherinterface.cpp b/src/libs/utils/launcherinterface.cpp
index 8e402f51c8a..bf49629a777 100644
--- a/src/libs/utils/launcherinterface.cpp
+++ b/src/libs/utils/launcherinterface.cpp
@@ -48,24 +48,11 @@ class LauncherProcess : public QProcess
 public:
     LauncherProcess(QObject *parent) : QProcess(parent)
     {
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0) && defined(Q_OS_UNIX)
-        setChildProcessModifier([this] { setupChildProcess_impl(); });
-#endif
-    }
-
-private:
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-    void setupChildProcess() override
-    {
-        setupChildProcess_impl();
-    }
-#endif
-
-    void setupChildProcess_impl()
-    {
 #ifdef Q_OS_UNIX
-        const auto pid = static_cast<pid_t>(processId());
-        setpgid(pid, pid);
+        setChildProcessModifier([this] {
+            const auto pid = static_cast<pid_t>(processId());
+            setpgid(pid, pid);
+        });
 #endif
     }
 };
diff --git a/src/libs/utils/navigationtreeview.cpp b/src/libs/utils/navigationtreeview.cpp
index 526bdbe7de6..33e55b452aa 100644
--- a/src/libs/utils/navigationtreeview.cpp
+++ b/src/libs/utils/navigationtreeview.cpp
@@ -68,12 +68,8 @@ void NavigationTreeView::scrollTo(const QModelIndex &index, QAbstractItemView::S
 
     QAbstractItemDelegate *delegate = itemDelegate(index);
     if (delegate) {
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-        const QStyleOptionViewItem option = viewOptions();
-#else
         QStyleOptionViewItem option;
         initViewItemOption(&option);
-#endif
         itemRect.setWidth(delegate->sizeHint(option, index).width());
     }
 
diff --git a/src/libs/utils/smallstring.h b/src/libs/utils/smallstring.h
index cabf6975a70..1e5d2cb567f 100644
--- a/src/libs/utils/smallstring.h
+++ b/src/libs/utils/smallstring.h
@@ -34,9 +34,7 @@
 
 #include <QByteArray>
 #include <QString>
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 #include <QStringEncoder>
-#endif
 
 #include <algorithm>
 #include <charconv>
@@ -488,7 +486,6 @@ public:
 
     void append(QStringView string)
     {
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
         QStringEncoder encoder{QStringEncoder::Utf8};
 
         constexpr size_type temporaryArraySize = Size * 6;
@@ -518,10 +515,6 @@ public:
         }
         *newEnd = 0;
         setSize(newEnd - data());
-#else
-        QByteArray array = string.toUtf8();
-        append(SmallStringView{array.data(), static_cast<size_type>(array.size())});
-#endif
     }
 
     BasicSmallString &operator+=(SmallStringView string)