diff --git a/src/client/plasmawindowmanagement.cpp b/src/client/plasmawindowmanagement.cpp
--- a/src/client/plasmawindowmanagement.cpp
+++ b/src/client/plasmawindowmanagement.cpp
@@ -361,12 +361,12 @@
     Q_UNUSED(window)
     Private *p = cast(data);
     const auto windows = p->wm->windows();
-    auto it = std::find_if(windows.begin(), windows.end(),
+    auto it = std::find_if(windows.constBegin(), windows.constEnd(),
         [parent] (const PlasmaWindow *w) {
             return *w == parent;
         }
     );
-    p->setParentWindow(it != windows.end() ? *it : nullptr);
+    p->setParentWindow(it != windows.constEnd() ? *it : nullptr);
 }
 
 void PlasmaWindow::Private::windowGeometryCallback(void *data, org_kde_plasma_window *window, int32_t x, int32_t y, uint32_t width, uint32_t height)
diff --git a/src/client/registry.cpp b/src/client/registry.cpp
--- a/src/client/registry.cpp
+++ b/src/client/registry.cpp
@@ -556,7 +556,7 @@
 namespace {
 static Registry::Interface nameToInterface(const char *interface)
 {
-    for (auto it = s_interfaces.begin(); it != s_interfaces.end(); ++it) {
+    for (auto it = s_interfaces.constBegin(); it != s_interfaces.constEnd(); ++it) {
         if (qstrcmp(interface, it.value().name) == 0) {
             return it.key();
         }
@@ -601,12 +601,12 @@
 
 bool Registry::Private::hasInterface(Registry::Interface interface) const
 {
-    auto it = std::find_if(m_interfaces.begin(), m_interfaces.end(),
+    auto it = std::find_if(m_interfaces.constBegin(), m_interfaces.constEnd(),
         [interface](const InterfaceData &data) {
             return data.interface == interface;
         }
     );
-    return it != m_interfaces.end();
+    return it != m_interfaces.constEnd();
 }
 
 QVector<Registry::AnnouncedInterface> Registry::Private::interfaces(Interface interface) const
@@ -873,10 +873,10 @@
 template <typename T>
 T *Registry::Private::bind(Registry::Interface interface, uint32_t name, uint32_t version) const
 {
-    auto it = std::find_if(m_interfaces.begin(), m_interfaces.end(), [=](const InterfaceData &data) {
+    auto it = std::find_if(m_interfaces.constBegin(), m_interfaces.constEnd(), [=](const InterfaceData &data) {
         return data.interface == interface && data.name == name && data.version >= version;
     });
-    if (it == m_interfaces.end()) {
+    if (it == m_interfaces.constEnd()) {
         qCDebug(KWAYLAND_CLIENT) << "Don't have interface " << int(interface) << "with name " << name << "and minimum version" << version;
         return nullptr;
     }
diff --git a/src/server/keyboard_interface.cpp b/src/server/keyboard_interface.cpp
--- a/src/server/keyboard_interface.cpp
+++ b/src/server/keyboard_interface.cpp
@@ -61,7 +61,7 @@
     wl_array keys;
     wl_array_init(&keys);
     const auto states = seat->pressedKeys();
-    for (auto it = states.begin(); it != states.end(); ++it) {
+    for (auto it = states.constBegin(); it != states.constEnd(); ++it) {
         uint32_t *k = reinterpret_cast<uint32_t*>(wl_array_add(&keys, sizeof(uint32_t)));
         *k = *it;
     }
diff --git a/src/server/output_interface.cpp b/src/server/output_interface.cpp
--- a/src/server/output_interface.cpp
+++ b/src/server/output_interface.cpp
@@ -115,8 +115,8 @@
 {
     for (auto it = s_privates.constBegin(); it != s_privates.constEnd(); ++it) {
         const auto &resources = (*it)->resources;
-        auto rit = std::find_if(resources.begin(), resources.end(), [native] (const ResourceData &data) { return data.resource == native; });
-        if (rit != resources.end()) {
+        auto rit = std::find_if(resources.constBegin(), resources.constEnd(), [native] (const ResourceData &data) { return data.resource == native; });
+        if (rit != resources.constEnd()) {
             return (*it);
         }
     }
@@ -153,26 +153,26 @@
 QSize OutputInterface::pixelSize() const
 {
     Q_D();
-    auto it = std::find_if(d->modes.begin(), d->modes.end(),
+    auto it = std::find_if(d->modes.constBegin(), d->modes.constEnd(),
         [](const Mode &mode) {
             return mode.flags.testFlag(ModeFlag::Current);
         }
     );
-    if (it == d->modes.end()) {
+    if (it == d->modes.constEnd()) {
         return QSize();
     }
     return (*it).size;
 }
 
 int OutputInterface::refreshRate() const
 {
     Q_D();
-    auto it = std::find_if(d->modes.begin(), d->modes.end(),
+    auto it = std::find_if(d->modes.constBegin(), d->modes.constEnd(),
         [](const Mode &mode) {
             return mode.flags.testFlag(ModeFlag::Current);
         }
     );
-    if (it == d->modes.end()) {
+    if (it == d->modes.constEnd()) {
         return 60000;
     }
     return (*it).refreshRate;
diff --git a/src/server/outputdevice_interface.cpp b/src/server/outputdevice_interface.cpp
--- a/src/server/outputdevice_interface.cpp
+++ b/src/server/outputdevice_interface.cpp
@@ -239,12 +239,12 @@
         emitChanges();
         return;
     } else {
-        auto idIt = std::find_if(d->modes.begin(), d->modes.end(),
+        auto idIt = std::find_if(d->modes.constBegin(), d->modes.constEnd(),
                                         [mode](const Mode &mode_it) {
                                             return mode.id == mode_it.id;
                                         }
         );
-        if (idIt != d->modes.end()) {
+        if (idIt != d->modes.constEnd()) {
             qCWarning(KWAYLAND_SERVER) << "Duplicate Mode id" << mode.id << ": not adding mode" << mode.size << mode.refreshRate;
             return;
         }
diff --git a/src/server/seat_interface.cpp b/src/server/seat_interface.cpp
--- a/src/server/seat_interface.cpp
+++ b/src/server/seat_interface.cpp
@@ -192,7 +192,7 @@
         return nullptr;
     }
 
-    for (auto it = interfaces.begin(); it != interfaces.end(); ++it) {
+    for (auto it = interfaces.constBegin(); it != interfaces.constEnd(); ++it) {
         if ((*it)->client() == surface->client()) {
             return (*it);
         }
@@ -209,7 +209,7 @@
         return ret;
     }
 
-    for (auto it = interfaces.begin(); it != interfaces.end(); ++it) {
+    for (auto it = interfaces.constBegin(); it != interfaces.constEnd(); ++it) {
         if ((*it)->client() == surface->client() && (*it)->resource()) {
             ret << *it;
         }
@@ -225,7 +225,7 @@
         return false;
     }
     bool calledAtLeastOne = false;
-    for (auto it = interfaces.begin(); it != interfaces.end(); ++it) {
+    for (auto it = interfaces.constBegin(); it != interfaces.constEnd(); ++it) {
         if ((*it)->client() == surface->client() && (*it)->resource()) {
             method(*it);
             calledAtLeastOne = true;
@@ -1271,7 +1271,7 @@
 {
     Q_D();
     QVector<quint32> keys;
-    for (auto it = d->keys.states.begin(); it != d->keys.states.end(); ++it) {
+    for (auto it = d->keys.states.constBegin(); it != d->keys.states.constEnd(); ++it) {
         if (it.value() == Private::Keyboard::State::Pressed) {
             keys << it.key();
         }
@@ -1502,7 +1502,7 @@
 {
     Q_D();
     const auto &serials = d->globalPointer.buttonSerials;
-    for (auto it = serials.begin(), end = serials.end(); it != end; it++) {
+    for (auto it = serials.constBegin(), end = serials.constEnd(); it != end; it++) {
         if (it.value() == serial) {
             return isPointerButtonPressed(it.key());
         }
diff --git a/tests/pasteclient.cpp b/tests/pasteclient.cpp
--- a/tests/pasteclient.cpp
+++ b/tests/pasteclient.cpp
@@ -149,11 +149,11 @@
                         return;
                     }
                     const auto &mimeTypes = dataOffer->offeredMimeTypes();
-                    auto it = std::find_if(mimeTypes.begin(), mimeTypes.end(),
+                    auto it = std::find_if(mimeTypes.constBegin(), mimeTypes.constEnd(),
                         [](const QMimeType &type) {
                             return type.inherits(QStringLiteral("text/plain"));
                         });
-                    if (it == mimeTypes.end()) {
+                    if (it == mimeTypes.constEnd()) {
                         return;
                     }
                     int pipeFds[2];