diff --git a/src/backends/drm/drm_output.cpp b/src/backends/drm/drm_output.cpp
index 655b7bb78a..d241850de3 100644
--- a/src/backends/drm/drm_output.cpp
+++ b/src/backends/drm/drm_output.cpp
@@ -508,7 +508,6 @@ void DrmOutput::renderCursorOpengl(const RenderTarget &renderTarget, const QSize
 
 void DrmOutput::renderCursorQPainter(const RenderTarget &renderTarget)
 {
-    const auto layer = m_pipeline->cursorLayer();
     const Cursor *cursor = Cursors::self()->currentCursor();
     const QImage cursorImage = cursor->image();
 
diff --git a/src/backends/x11/common/x11_common_egl_backend.cpp b/src/backends/x11/common/x11_common_egl_backend.cpp
index 4ede0364f1..a0adfefcfc 100644
--- a/src/backends/x11/common/x11_common_egl_backend.cpp
+++ b/src/backends/x11/common/x11_common_egl_backend.cpp
@@ -35,7 +35,7 @@ EglOnXBackend::EglOnXBackend(Display *display)
     setIsDirectRendering(true);
 }
 
-EglOnXBackend::EglOnXBackend(xcb_connection_t *connection, Display *display, xcb_window_t rootWindow, int screenNumber, xcb_window_t renderingWindow)
+EglOnXBackend::EglOnXBackend(xcb_connection_t *connection, Display *display, xcb_window_t rootWindow, xcb_window_t renderingWindow)
     : AbstractEglBackend()
     , m_overlayWindow(nullptr)
     , surfaceHasSubPost(0)
diff --git a/src/backends/x11/common/x11_common_egl_backend.h b/src/backends/x11/common/x11_common_egl_backend.h
index edc923e29f..2189168920 100644
--- a/src/backends/x11/common/x11_common_egl_backend.h
+++ b/src/backends/x11/common/x11_common_egl_backend.h
@@ -29,7 +29,7 @@ class KWIN_EXPORT EglOnXBackend : public AbstractEglBackend
 
 public:
     EglOnXBackend(Display *display);
-    explicit EglOnXBackend(xcb_connection_t *connection, Display *display, xcb_window_t rootWindow, int screenNumber, xcb_window_t renderingWindow);
+    explicit EglOnXBackend(xcb_connection_t *connection, Display *display, xcb_window_t rootWindow, xcb_window_t renderingWindow);
     ~EglOnXBackend() override;
     OverlayWindow *overlayWindow() const override;
     void init() override;
diff --git a/src/backends/x11/windowed/x11_windowed_egl_backend.cpp b/src/backends/x11/windowed/x11_windowed_egl_backend.cpp
index 2c10859925..84239b5f40 100644
--- a/src/backends/x11/windowed/x11_windowed_egl_backend.cpp
+++ b/src/backends/x11/windowed/x11_windowed_egl_backend.cpp
@@ -72,7 +72,7 @@ QRegion X11WindowedEglOutput::lastDamage() const
 }
 
 X11WindowedEglBackend::X11WindowedEglBackend(X11WindowedBackend *backend)
-    : EglOnXBackend(backend->connection(), backend->display(), backend->rootWindow(), backend->screenNumer(), XCB_WINDOW_NONE)
+    : EglOnXBackend(backend->connection(), backend->display(), backend->rootWindow(), XCB_WINDOW_NONE)
     , m_backend(backend)
 {
 }
diff --git a/src/debug_console.cpp b/src/debug_console.cpp
index 7eaa284f3e..153be4cc05 100644
--- a/src/debug_console.cpp
+++ b/src/debug_console.cpp
@@ -1605,6 +1605,7 @@ QModelIndex DataSourceModel::index(int row, int column, const QModelIndex &paren
 
 QModelIndex DataSourceModel::parent(const QModelIndex &child) const
 {
+    Q_UNUSED(child)
     return QModelIndex();
 }
 
diff --git a/src/wayland/datadevicemanager_interface.cpp b/src/wayland/datadevicemanager_interface.cpp
index 59001ae51f..ae54331d85 100644
--- a/src/wayland/datadevicemanager_interface.cpp
+++ b/src/wayland/datadevicemanager_interface.cpp
@@ -44,7 +44,7 @@ void DataDeviceManagerInterfacePrivate::data_device_manager_create_data_source(R
         wl_resource_post_no_memory(resource->handle);
         return;
     }
-    DataSourceInterface *dataSource = new DataSourceInterface(q, data_source_resource);
+    DataSourceInterface *dataSource = new DataSourceInterface(data_source_resource);
     Q_EMIT q->dataSourceCreated(dataSource);
 }
 
diff --git a/src/wayland/datasource_interface.cpp b/src/wayland/datasource_interface.cpp
index 7789027d26..6ed2180514 100644
--- a/src/wayland/datasource_interface.cpp
+++ b/src/wayland/datasource_interface.cpp
@@ -93,7 +93,7 @@ void DataSourceInterfacePrivate::data_source_set_actions(Resource *resource, uin
     }
 }
 
-DataSourceInterface::DataSourceInterface(DataDeviceManagerInterface *parent, wl_resource *resource)
+DataSourceInterface::DataSourceInterface(wl_resource *resource)
     : d(new DataSourceInterfacePrivate(this, resource))
 {
     if (d->resource()->version() < WL_DATA_SOURCE_ACTION_SINCE_VERSION) {
diff --git a/src/wayland/datasource_interface.h b/src/wayland/datasource_interface.h
index 69f437fff2..a3bd7c8bd5 100644
--- a/src/wayland/datasource_interface.h
+++ b/src/wayland/datasource_interface.h
@@ -51,7 +51,7 @@ public:
 
 private:
     friend class DataDeviceManagerInterfacePrivate;
-    explicit DataSourceInterface(DataDeviceManagerInterface *parent, wl_resource *parentResource);
+    explicit DataSourceInterface(wl_resource *resource);
 
     std::unique_ptr<DataSourceInterfacePrivate> d;
 };
diff --git a/src/wayland/primaryselectiondevicemanager_v1_interface.cpp b/src/wayland/primaryselectiondevicemanager_v1_interface.cpp
index 5cf42fb54e..f8bd2a6a74 100644
--- a/src/wayland/primaryselectiondevicemanager_v1_interface.cpp
+++ b/src/wayland/primaryselectiondevicemanager_v1_interface.cpp
@@ -41,7 +41,7 @@ void PrimarySelectionDeviceManagerV1InterfacePrivate::zwp_primary_selection_devi
         wl_resource_post_no_memory(resource->handle);
         return;
     }
-    PrimarySelectionSourceV1Interface *dataSource = new PrimarySelectionSourceV1Interface(q, data_source_resource);
+    PrimarySelectionSourceV1Interface *dataSource = new PrimarySelectionSourceV1Interface(data_source_resource);
     Q_EMIT q->dataSourceCreated(dataSource);
 }
 
diff --git a/src/wayland/primaryselectionsource_v1_interface.cpp b/src/wayland/primaryselectionsource_v1_interface.cpp
index 38ceb55b21..a38ffbd7de 100644
--- a/src/wayland/primaryselectionsource_v1_interface.cpp
+++ b/src/wayland/primaryselectionsource_v1_interface.cpp
@@ -55,7 +55,7 @@ void PrimarySelectionSourceV1InterfacePrivate::zwp_primary_selection_source_v1_d
     wl_resource_destroy(resource->handle);
 }
 
-PrimarySelectionSourceV1Interface::PrimarySelectionSourceV1Interface(PrimarySelectionDeviceManagerV1Interface *parent, ::wl_resource *resource)
+PrimarySelectionSourceV1Interface::PrimarySelectionSourceV1Interface(::wl_resource *resource)
     : d(new PrimarySelectionSourceV1InterfacePrivate(this, resource))
 {
 }
diff --git a/src/wayland/primaryselectionsource_v1_interface.h b/src/wayland/primaryselectionsource_v1_interface.h
index d02a42566e..b405016bf7 100644
--- a/src/wayland/primaryselectionsource_v1_interface.h
+++ b/src/wayland/primaryselectionsource_v1_interface.h
@@ -34,7 +34,7 @@ public:
 
 private:
     friend class PrimarySelectionDeviceManagerV1InterfacePrivate;
-    explicit PrimarySelectionSourceV1Interface(PrimarySelectionDeviceManagerV1Interface *parent, ::wl_resource *resource);
+    explicit PrimarySelectionSourceV1Interface(::wl_resource *resource);
 
     std::unique_ptr<PrimarySelectionSourceV1InterfacePrivate> d;
 };
diff --git a/src/workspace.cpp b/src/workspace.cpp
index 7491cc3f4b..7ddce8eb9d 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -310,9 +310,6 @@ void Workspace::initializeX11()
     // Select windowmanager privileges
     selectWmInputEventMask();
 
-    // Compatibility
-    int32_t data = 1;
-
     if (kwinApp()->operationMode() == Application::OperationModeX11) {
         m_wasUserInteractionFilter.reset(new WasUserInteractionX11Filter);
         m_movingClientFilter.reset(new MovingClientX11Filter);