diff --git a/uppsrc/CtrlCore/CtrlCore.h b/uppsrc/CtrlCore/CtrlCore.h
index 209942633..6d16e2884 100644
--- a/uppsrc/CtrlCore/CtrlCore.h
+++ b/uppsrc/CtrlCore/CtrlCore.h
@@ -38,6 +38,9 @@
 			#ifndef flagGTK
 				#define flagGTK
 			#endif
+			#ifdef flagWAYLAND
+				#define GUI_GTK_WAYLAND
+			#endif
 			#define GUIPLATFORM_INCLUDE "Gtk.h"
 		#endif
 	#endif
diff --git a/uppsrc/CtrlCore/CtrlCore.upp b/uppsrc/CtrlCore/CtrlCore.upp
index f498c239d..f20659b4e 100644
--- a/uppsrc/CtrlCore/CtrlCore.upp
+++ b/uppsrc/CtrlCore/CtrlCore.upp
@@ -91,8 +91,10 @@ file
 	GtkDrawOp.cpp,
 	GtkDrawText.cpp,
 	GtkDrawImage.cpp,
+	GdkBackend.cpp,
 	GdkImage.cpp,
 	GtkUtil.cpp,
+	GtkCSD.cpp,
 	GtkX11Util.cpp,
 	GtkCtrl.h,
 	GtkCtrl.cpp,
diff --git a/uppsrc/CtrlCore/CtrlDraw.cpp b/uppsrc/CtrlCore/CtrlDraw.cpp
index 7dab14eb5..283ec5a6c 100644
--- a/uppsrc/CtrlCore/CtrlDraw.cpp
+++ b/uppsrc/CtrlCore/CtrlDraw.cpp
@@ -18,7 +18,8 @@ static void sCheckGuiLock()
 void Ctrl::RefreshFrame(const Rect& r) {
 	sCheckGuiLock();
 	GuiLock __; // Beware: Even if we have ThreadHasGuiLock ASSERT, we still can be the main thread!
-	if(!IsOpen() || !IsVisible() || r.IsEmpty()) return;
+	if(!IsOpen() || !IsVisible() || r.IsEmpty())
+		return;
 	LTIMING("RefreshFrame");
 	LLOG("RefreshRect " << Name() << ' ' << r);
 	if(GuiPlatformRefreshFrameSpecial(r))
diff --git a/uppsrc/CtrlCore/GdkBackend.cpp b/uppsrc/CtrlCore/GdkBackend.cpp
new file mode 100644
index 000000000..b67e620fc
--- /dev/null
+++ b/uppsrc/CtrlCore/GdkBackend.cpp
@@ -0,0 +1,67 @@
+#include "CtrlCore.h"
+
+#ifdef GUI_GTK
+
+#ifdef GDK_WINDOWING_X11
+#include <gdk/gdkx.h>
+#endif
+#ifdef GDK_WINDOWING_WAYLAND
+#include <gdk/gdkwayland.h>
+#endif
+
+namespace Upp {
+namespace GdkBackend {
+
+Type Get()
+{
+	static auto backend = Type::UNKNOWN;
+	if (backend != Type::UNKNOWN) {
+		return backend;
+	}
+	
+	auto* display = gdk_display_get_default();
+#ifdef GDK_WINDOWING_X11
+	if (GDK_IS_X11_DISPLAY(display)) {
+		backend = Type::X11;
+		return backend;
+	}
+#endif
+#ifdef GDK_WINDOWING_WAYLAND
+	if (GDK_IS_WAYLAND_DISPLAY(display)) {
+		backend = Type::WAYLAND;
+		return backend;
+	}
+#endif
+	return backend;
+}
+
+bool IsWayland()
+{
+	return Get() == Type::WAYLAND;
+}
+
+bool IsX11()
+{
+	return Get() == Type::X11;
+}
+
+bool IsRunningOnWayland()
+{
+	static bool running = GetEnv("XDG_SESSION_TYPE") == "wayland";
+	return running;
+}
+
+}
+
+String ToString(GdkBackend::Type t)
+{
+	switch (t) {
+		case GdkBackend::Type::X11: return "X11";
+		case GdkBackend::Type::WAYLAND: return "Wayland";
+		default: return "Unknown";
+	}
+}
+
+}
+
+#endif
diff --git a/uppsrc/CtrlCore/Gtk.h b/uppsrc/CtrlCore/Gtk.h
index 1b25eca0b..9932b9267 100644
--- a/uppsrc/CtrlCore/Gtk.h
+++ b/uppsrc/CtrlCore/Gtk.h
@@ -164,11 +164,51 @@ public:
 	~ImageGdk();
 };
 
+class GtkCSD final {
+public:
+	static bool IsSSDSupported();
+	
+public:
+	GtkCSD(GdkWindowTypeHint hint);
+	
+	bool IsEnable() const      { return enable; }
+	
+	int ExtraWidth() const   { return left_margin + right_margin; }
+	int ExtraHeight() const  { return top_margin + bottom_margin; }
+	
+	int LeftMaring() const   { return left_margin; }
+	int RightMargin() const  { return right_margin; }
+	int TopMargin() const    { return top_margin; }
+	int BottomMargin() const { return bottom_margin; }
+	
+private:
+	void FindMargins(GdkWindowTypeHint hint);
+	
+private:
+	int left_margin = 0, right_margin = 0, top_margin = 0, bottom_margin = 0;
+	bool enable = false;
+};
+
+namespace GdkBackend {
+
+	enum class Type {
+		X11,
+		WAYLAND,
+		UNKNOWN
+	};
+	
+	Type Get();
+	bool IsX11();
+	bool IsWayland();
+	
+	bool IsRunningOnWayland();
+}
+
+String ToString(GdkBackend::Type b);
+
 String FilesClipFromUrisFree(gchar **uris);
 String ImageClipFromPixbufUnref(GdkPixbuf *pixbuf);
 
-bool   RunningOnWayland();
-
 GdkAtom GAtom(const String& id);
 
 #ifdef GDK_WINDOWING_X11
@@ -183,9 +223,12 @@ Vector<int> GetPropertyInts(GdkWindow *w, const char *property);
 
 #define GUIPLATFORM_CTRL_TOP_DECLS \
 	GtkWidget            *window; \
-	GtkIMContext         *im_context; \
+	GtkWidget            *header = nullptr; \
+	GtkWidget            *drawing_area = nullptr; \
+	GtkIMContext         *im_context = nullptr; \
 	GtkIMContext         *im_context_simple; \
 	GtkIMContext         *im_context_multi; \
+	One<GtkCSD>           csd; \
 	int64                 cursor_id; \
 	int                   id; \
 
diff --git a/uppsrc/CtrlCore/GtkAfter.h b/uppsrc/CtrlCore/GtkAfter.h
index d15cda88d..1f8346ea5 100644
--- a/uppsrc/CtrlCore/GtkAfter.h
+++ b/uppsrc/CtrlCore/GtkAfter.h
@@ -9,7 +9,7 @@ public:
 
 class DHCtrl : Ctrl {};
 
-void InitGtkApp(int argc, char **argv, const char **envptr);
+bool InitGtkApp(int argc, char **argv, const char **envptr);
 void ExitGtkApp();
 
 #define GUI_APP_MAIN \
@@ -18,7 +18,8 @@ void GuiMainFn_(); \
 int main(int argc, char **argv, const char **envptr) { \
 	UPP::AppInit__(argc, (const char **)argv, envptr); \
 	GUI_APP_MAIN_HOOK \
-	UPP::InitGtkApp(argc, argv, envptr); \
+	if (!UPP::InitGtkApp(argc, argv, envptr)) \
+		return -1; \
 	UPP::AppExecute__(GuiMainFn_); \
 	UPP::Ctrl::CloseTopCtrls(); \
 	UPP::ExitGtkApp(); \
diff --git a/uppsrc/CtrlCore/GtkApp.cpp b/uppsrc/CtrlCore/GtkApp.cpp
index 5471eda34..cd62d4711 100644
--- a/uppsrc/CtrlCore/GtkApp.cpp
+++ b/uppsrc/CtrlCore/GtkApp.cpp
@@ -66,21 +66,27 @@ void Ctrl::ThemeChanged(void *)
 	PostReSkin();
 }
 
-void InitGtkApp(int argc, char **argv, const char **envptr)
+bool InitGtkApp(int argc, char **argv, const char **envptr)
 {
 	LLOG(rmsecs() << " InitGtkApp");
 	
-	XInitThreads(); // otherwise there are errors despide GuiLock
-	
-	running_on_wayland = GetEnv("XDG_SESSION_TYPE") == "wayland";
-
 #if GTK_CHECK_VERSION(3, 10, 0)
-	gdk_set_allowed_backends("x11"); // this fixes some wayland issues
+	String backends = "x11,wayland";
+#ifdef GUI_GTK_WAYLAND
+	backends = "wayland,x11";
+#endif
+	gdk_set_allowed_backends(backends);
 #endif
 
+	if (!gtk_init_check(&argc, &argv)) {
+		Cerr() << t_("Failed to initialized GTK app!") << "\n";
+		return false;
+	}
+	if (GdkBackend::IsX11()) {
+		XInitThreads(); // otherwise there are errors despide GuiLock
+	}
 	EnterGuiMutex();
-	gtk_init(&argc, &argv);
-
+	
 	Ctrl::SetUHDEnabled(true);
 	
 	Ctrl::scale = 1;
@@ -92,15 +98,19 @@ void InitGtkApp(int argc, char **argv, const char **envptr)
 	Ctrl::ReSkin();
 	g_timeout_add(20, (GSourceFunc) Ctrl::TimeHandler, NULL);
 	InstallPanicMessageBox(Ctrl::PanicMsgBox);
-	gdk_window_add_filter(NULL, Ctrl::RootKeyFilter, NULL);
+	if (GdkBackend::IsX11())
+		gdk_window_add_filter(NULL, Ctrl::RootKeyFilter, NULL);
 #if CATCH_ERRORS
 	g_log_set_default_handler (CatchError, 0);
 #endif
-	GtkSettings *settings = gtk_settings_get_default ();
+
+	GtkSettings *settings = gtk_settings_get_default();
 	if(settings) {
 		g_signal_connect_swapped(settings, "notify::gtk-theme-name", G_CALLBACK(Ctrl::ThemeChanged), NULL);
 		g_signal_connect_swapped(settings, "notify::gtk-application-prefer-dark-theme", G_CALLBACK(Ctrl::ThemeChanged), NULL);
 	}
+	
+	return true;
 }
 
 void ExitGtkApp()
diff --git a/uppsrc/CtrlCore/GtkCSD.cpp b/uppsrc/CtrlCore/GtkCSD.cpp
new file mode 100644
index 000000000..941143099
--- /dev/null
+++ b/uppsrc/CtrlCore/GtkCSD.cpp
@@ -0,0 +1,82 @@
+#include <CtrlCore/CtrlCore.h>
+
+#ifdef GUI_GTK
+
+namespace Upp {
+
+bool GtkCSD::IsSSDSupported()
+{
+	if (GdkBackend::IsX11()) {
+		return false;
+	}
+	
+	// TODO: Rewrite to negotiate with window manager once XDG decoration protocol will be
+	// stable. (https://wayland.app/protocols/xdg-decoration-unstable-v1)
+	
+	// NOTE: Server side decoration are optional. It might be supported by Window manager or
+	// not. Let's have a list of desktop environments on which we tested it works correctly.
+	auto desktop = GetEnv("XDG_SESSION_DESKTOP");
+	if (desktop == "KDE") {
+		return true;
+		//return true;
+	}
+	
+	return false;
+}
+
+GtkCSD::GtkCSD(GdkWindowTypeHint hint)
+{
+	if (!GdkBackend::IsWayland())
+		return;
+	if (IsSSDSupported()) {
+		if (hint == GDK_WINDOW_TYPE_HINT_POPUP_MENU) {
+			FindMargins(hint);
+			enable = true;
+		}
+		
+		return;
+	}
+	if (hint == GDK_WINDOW_TYPE_HINT_COMBO) {
+		return;
+	}
+	
+	FindMargins(hint);
+	enable = true;
+}
+
+void GtkCSD::FindMargins(GdkWindowTypeHint hint)
+{
+	GtkWidget* win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+	GtkWidget* header;
+	if (findarg(hint, GDK_WINDOW_TYPE_HINT_POPUP_MENU) >= 0) {
+		header = gtk_drawing_area_new();
+		gtk_widget_set_size_request(header, 1, 1);
+		gtk_window_set_titlebar((GtkWindow *)win, header);
+	} else {
+		header = gtk_header_bar_new();
+		gtk_header_bar_set_show_close_button(GTK_HEADER_BAR(header), TRUE);
+		gtk_window_set_titlebar((GtkWindow *)win, header);
+	}
+	GtkWidget* drawing_area = gtk_drawing_area_new();
+	gtk_container_add(GTK_CONTAINER(win), drawing_area);
+	gtk_widget_show_all(win);
+	
+	gdk_window_get_origin(gtk_widget_get_window(drawing_area), &left_margin, &top_margin);
+	
+	gint drawing_area_width = gtk_widget_get_allocated_width(drawing_area);
+	gint drawing_area_height = gtk_widget_get_allocated_height(drawing_area);
+	
+	gint win_width = gtk_widget_get_allocated_width(win);
+	gint win_height = gtk_widget_get_allocated_height(win);
+	
+	right_margin = win_width - left_margin - drawing_area_width;
+	bottom_margin = win_height - top_margin - drawing_area_height;
+	
+	gtk_widget_destroy(drawing_area);
+	gtk_widget_destroy(header);
+	gtk_widget_destroy(win);
+}
+
+}
+
+#endif
diff --git a/uppsrc/CtrlCore/GtkCreate.cpp b/uppsrc/CtrlCore/GtkCreate.cpp
index 3a5680e93..edb222741 100644
--- a/uppsrc/CtrlCore/GtkCreate.cpp
+++ b/uppsrc/CtrlCore/GtkCreate.cpp
@@ -30,22 +30,42 @@ void Ctrl::Create(Ctrl *owner, bool popup)
 	w.gdk = nullptr;
 
 	TopWindow *tw = dynamic_cast<TopWindow *>(this);
+	GdkWindowTypeHint type_hint;
 	if(popup && !owner) {
 		gtk_window_set_decorated(gtk(), FALSE);
-		// gtk_window_set_has_frame(gtk(), FALSE);
-		gtk_window_set_type_hint(gtk(), GDK_WINDOW_TYPE_HINT_POPUP_MENU);
+		type_hint = GDK_WINDOW_TYPE_HINT_POPUP_MENU;
 	}
-	else
-		gtk_window_set_type_hint(gtk(), popup ? GDK_WINDOW_TYPE_HINT_COMBO
-		                                : tw && tw->tool ? GDK_WINDOW_TYPE_HINT_UTILITY
-		                                : owner ? GDK_WINDOW_TYPE_HINT_DIALOG
-		                                : GDK_WINDOW_TYPE_HINT_NORMAL);
-
+	else {
+		type_hint = popup ? GDK_WINDOW_TYPE_HINT_COMBO
+		                  : tw && tw->tool ? GDK_WINDOW_TYPE_HINT_UTILITY
+		                  : owner ? GDK_WINDOW_TYPE_HINT_DIALOG
+		                  : GDK_WINDOW_TYPE_HINT_NORMAL;
+	}
+	gtk_window_set_type_hint(gtk(), type_hint);
+	
+	top->csd.Create(type_hint);
+	if (top->csd->IsEnable()) {
+		if (findarg(type_hint, GDK_WINDOW_TYPE_HINT_POPUP_MENU) >= 0) {
+			top->header = gtk_drawing_area_new();
+			gtk_widget_set_size_request(top->header, 1, 1);
+			gtk_window_set_titlebar(gtk(), top->header);
+		} else {
+			top->header = gtk_header_bar_new();
+			gtk_header_bar_set_show_close_button(GTK_HEADER_BAR(top->header), TRUE);
+			gtk_window_set_titlebar(gtk(), top->header);
+		}
+		
+		top->drawing_area = gtk_drawing_area_new();
+		gtk_widget_set_can_focus(top->drawing_area, TRUE);
+	} else {
+		top->drawing_area = top->window;
+	}
+	
 	top->cursor_id = -1;
 
-	gtk_widget_set_events(top->window, GDK_ALL_EVENTS_MASK & ~GDK_POINTER_MOTION_HINT_MASK);
-	g_signal_connect(top->window, "event", G_CALLBACK(GtkEvent), (gpointer)(uintptr_t)top->id);
-	g_signal_connect(top->window, "draw", G_CALLBACK(GtkDraw), (gpointer)(uintptr_t)top->id);
+	gtk_widget_set_events(top->drawing_area, GDK_ALL_EVENTS_MASK & ~GDK_POINTER_MOTION_HINT_MASK & ~GDK_SMOOTH_SCROLL_MASK);
+	g_signal_connect(top->drawing_area, "event", G_CALLBACK(GtkEvent), (gpointer)(uintptr_t)top->id);
+	g_signal_connect(top->drawing_area, "draw", G_CALLBACK(GtkDraw), (gpointer)(uintptr_t)top->id);
 
 	GdkWindowTypeHint hint = gtk_window_get_type_hint(gtk());
 	if(tw && findarg(hint, GDK_WINDOW_TYPE_HINT_NORMAL, GDK_WINDOW_TYPE_HINT_DIALOG, GDK_WINDOW_TYPE_HINT_UTILITY) >= 0)
@@ -53,15 +73,20 @@ void Ctrl::Create(Ctrl *owner, bool popup)
 
 	Rect r = GetRect();
 	
-	gtk_window_set_default_size (gtk(), LSC(r.GetWidth()), LSC(r.GetHeight()));
-	
+	// TODO: Normalize
+	gtk_window_set_default_size(gtk(), LSC(r.GetWidth()), LSC(r.GetHeight()));
 	gtk_window_move(gtk(), LSC(r.left), LSC(r.top));
 	gtk_window_resize(gtk(), LSC(r.GetWidth()), LSC(r.GetHeight()));
+		
+	if (top->header) {
+		gtk_container_add(GTK_CONTAINER(top->window), top->drawing_area);
+		gtk_widget_show_all(top->window);
+	} else {
+		gtk_widget_realize(top->window);
+	}
 	
-	gtk_widget_realize(top->window);
-
 	w.gdk = gtk_widget_get_window(top->window);
-
+	
 	if(owner && owner->top)
 		gtk_window_set_transient_for(gtk(), owner->gtk());
 	gtk_widget_set_app_paintable(top->window, TRUE);
@@ -114,8 +139,10 @@ void Ctrl::WndDestroy()
 			activeCtrl = owner;
 	}
 	Top *top = GetTop();
-	if(top->im_context)
+	if(top->im_context) {
 		g_object_unref(top->im_context);
+		top->im_context = nullptr;
+	}
 	gtk_widget_destroy(top->window);
 	isopen = false;
 	popup = false;
@@ -124,8 +151,14 @@ void Ctrl::WndDestroy()
 	int q = FindCtrl(this);
 	if(q >= 0)
 		wins.Remove(q);
-	if(owner)
+	if(owner) {
+		if(owner->utop->csd->IsEnable()) {
+			// TODO: This fix the problem with keyboard when backing to original window, but
+			// the previous control is not being focused like it should be.
+			gtk_window_set_focus(owner->gtk(), owner->utop->drawing_area);
+		}
 		owner->WndUpdate();
+	}
 	TopWindow *w = dynamic_cast<TopWindow *>(this);
 	if(w && w->overlapped.GetWidth() && w->overlapped.GetHeight())
 		SetRect(w->overlapped);
diff --git a/uppsrc/CtrlCore/GtkCtrl.cpp b/uppsrc/CtrlCore/GtkCtrl.cpp
index 75cf19c47..f846757bd 100644
--- a/uppsrc/CtrlCore/GtkCtrl.cpp
+++ b/uppsrc/CtrlCore/GtkCtrl.cpp
@@ -2,6 +2,10 @@
 
 #ifdef GUI_GTK
 
+#ifndef PLATFORM_OPENBSD
+#undef CurrentTime
+#endif
+
 #define LLOG(x) // DLOG(x)
 
 namespace Upp {
@@ -76,8 +80,6 @@ GtkWindow *Ctrl::gtk() const
 	return top ? (GtkWindow *)top->window : NULL;
 }
 
-
-
 }
 
 #endif
diff --git a/uppsrc/CtrlCore/GtkCtrl.h b/uppsrc/CtrlCore/GtkCtrl.h
index f77436787..fdb3d7033 100644
--- a/uppsrc/CtrlCore/GtkCtrl.h
+++ b/uppsrc/CtrlCore/GtkCtrl.h
@@ -168,7 +168,7 @@ _DBG_
 	                        guint time, gpointer user_data, bool paste);
 	static bool   ProcessInvalids();
 
-	friend void InitGtkApp(int argc, char **argv, const char **envptr);
+	friend bool InitGtkApp(int argc, char **argv, const char **envptr);
 	friend void GuiPlatformGripResize(TopWindow *q);
 
 public: // really private:
@@ -187,7 +187,7 @@ public: // really private:
 	static Gclipboard& gclipboard();
 	static Gclipboard& gselection();
 	static String      RenderPrimarySelection(const Value& fmt);
-
+	
 	static Vector<Event<>> hotkey;
 	static Vector<dword>   keyhot;
 	static Vector<dword>   modhot;
diff --git a/uppsrc/CtrlCore/GtkEvent.cpp b/uppsrc/CtrlCore/GtkEvent.cpp
index 70a9c1fa3..35e9d6911 100644
--- a/uppsrc/CtrlCore/GtkEvent.cpp
+++ b/uppsrc/CtrlCore/GtkEvent.cpp
@@ -2,6 +2,10 @@
 
 #ifdef GUI_GTK
 
+#ifndef PLATFORM_OPENBSD
+#undef CurrentTime
+#endif
+
 namespace Upp {
 
 #define LLOG(x)    // DLOG(x)
@@ -89,6 +93,7 @@ gboolean Ctrl::GtkDraw(GtkWidget *widget, cairo_t *cr, gpointer user_data)
 
 		SystemDraw w(cr);
 		painting = true;
+		
 		double x1, y1, x2, y2;
 		cairo_clip_extents (cr, &x1, &y1, &x2, &y2);
 		Rect r = RectC((int)x1, (int)y1, (int)ceil(x2 - x1), (int)ceil(y2 - y1));
@@ -136,7 +141,7 @@ gboolean Ctrl::GtkEvent(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 		p->CancelPreedit();
 		if(p) {
 			Top *top = p->GetTop();
-			if(top) {
+			if(top && top->im_context) {
 				if(((GdkEventFocus *)event)->in)
 					gtk_im_context_focus_in(top->im_context);
 				else
diff --git a/uppsrc/CtrlCore/GtkTop.cpp b/uppsrc/CtrlCore/GtkTop.cpp
index c23a6909d..d4d746dc5 100644
--- a/uppsrc/CtrlCore/GtkTop.cpp
+++ b/uppsrc/CtrlCore/GtkTop.cpp
@@ -14,7 +14,7 @@ Rect Ctrl::GetFrameMargins()
 	return frameMargins != Rect(0, 0, 0, 0) ? frameMargins : Rect(8, 32, 8, 8);
 }
 
-void    TopWindow::SyncSizeHints()
+void TopWindow::SyncSizeHints()
 {
 	GuiLock __;
 	if(!top)
@@ -25,13 +25,13 @@ void    TopWindow::SyncSizeHints()
 	Size sz = sz0;
 	if(sizeable)
 		sz = GetMinSize();
-	m.min_width = LSC(sz.cx);
-	m.min_height = LSC(sz.cy);
+	m.min_width = LSC(sz.cx + utop->csd->ExtraWidth());
+	m.min_height = LSC(sz.cy + utop->csd->ExtraHeight());
 	sz = sz0;
 	if(sizeable)
 		sz = GetMaxSize();
-	m.max_width = LSC(sz.cx);
-	m.max_height = LSC(sz.cy);
+	m.max_width = LSC(sz.cx + utop->csd->ExtraWidth());
+	m.max_height = LSC(sz.cy + utop->csd->ExtraHeight());
 	gtk_window_set_resizable(gtk(), sizeable);
 	Top *top = GetTop();
 	if(top) {
diff --git a/uppsrc/CtrlCore/GtkWnd.cpp b/uppsrc/CtrlCore/GtkWnd.cpp
index fcb38bbf3..2522568a0 100644
--- a/uppsrc/CtrlCore/GtkWnd.cpp
+++ b/uppsrc/CtrlCore/GtkWnd.cpp
@@ -111,7 +111,7 @@ void  Ctrl::SetMouseCursor(const Image& image)
 		if(c && topctrl->IsOpen()) {
 			gdk_window_set_cursor(topctrl->gdk(), c);
 			g_object_unref(c);
-			if(RunningOnWayland()) // wayland is broken, need some paint to change the cursor...
+			if(GdkBackend::IsX11() && GdkBackend::IsRunningOnWayland()) // wayland is broken, need some paint to change the cursor...
 				topctrl->Refresh(0, 0, 1, 1);
 			gdk_display_flush(gdk_display_get_default()); // Make it visible immediately
 		}
@@ -153,14 +153,28 @@ void Ctrl::UnregisterSystemHotKey(int id)
 Rect Ctrl::GetWndScreenRect() const
 {
 	GuiLock __;
-	if(IsOpen()) {
-		gint x, y;
-		gdk_window_get_position(gdk(), &x, &y);
-		gint width = gdk_window_get_width(gdk());
-		gint height = gdk_window_get_height(gdk());
-		return SCL(x, y, width, height);
+	if(!IsOpen()) {
+		return Null;
 	}
-	return Null;
+	
+	gint x, y;
+	gint width, height;
+	
+	if (GdkBackend::IsWayland()) {
+		if(top && utop->csd->IsEnable()) {
+			gdk_window_get_origin(gtk_widget_get_window(utop->drawing_area), &x, &y);
+			width = gtk_widget_get_allocated_width(utop->drawing_area);
+			height = gtk_widget_get_allocated_height(utop->drawing_area);
+		} else {
+			gdk_window_get_geometry(gdk(), &x, &y, &width, &height);
+		}
+	} else {
+		gdk_window_get_position(gdk(), &x, &y);
+		width = gdk_window_get_width(gdk());
+		height = gdk_window_get_height(gdk());
+	}
+	
+	return SCL(x, y, width, height);
 }
 
 void Ctrl::WndShow(bool b)
@@ -169,7 +183,6 @@ void Ctrl::WndShow(bool b)
 	LLOG("WndShow " << Name() << ", " << b);
 	Top *top = GetTop();
 	if(IsOpen() && top) {
-		
 		if(b)
 			gtk_widget_show_now(top->window);
 		else
@@ -197,20 +210,24 @@ Rect Ctrl::GetWorkArea() const
 void Ctrl::GetWorkArea(Array<Rect>& rc)
 {
 	GuiLock __;
+	rc.Clear();
 #if GTK_CHECK_VERSION(3, 22, 0)
 	GdkDisplay *s = gdk_display_get_default();
 	int n = gdk_display_get_n_monitors(s);
-	rc.Clear();
 	Vector<int> netwa;
 	for(int i = 0; i < n; i++) {
 		GdkRectangle rr;
-		gdk_monitor_get_workarea(gdk_display_get_monitor(s, i), &rr);
+		auto *pMonitor = gdk_display_get_monitor(s, i);
+		if (GdkBackend::IsWayland()) {
+			gdk_monitor_get_geometry(pMonitor, &rr);
+		} else {
+			gdk_monitor_get_workarea(pMonitor, &rr);
+		}
 		rc.Add(SCL(rr.x, rr.y, rr.width, rr.height));
 	}
 #else
 	GdkScreen *s = gdk_screen_get_default();
 	int n = gdk_screen_get_n_monitors(s);
-	rc.Clear();
 	Vector<int> netwa;
 	for(int i = 0; i < n; i++) {
 		GdkRectangle rr;
@@ -236,19 +253,45 @@ Rect Ctrl::GetVirtualWorkArea()
 Rect Ctrl::GetVirtualScreenArea()
 {
 	GuiLock __;
+	auto pRootWindow = gdk_screen_get_root_window(gdk_screen_get_default());
+	if (!pRootWindow) {
+		ASSERT("Failed to obtain root window!");
+		return Rect();
+	}
+#if GTK_CHECK_VERSION(3, 22, 0)
+	if (GdkBackend::IsWayland()) {
+		GdkRectangle rr;
+		auto *pDisplay = gdk_display_get_default();
+		auto *pMonitor = gdk_display_get_monitor_at_window(pDisplay, pRootWindow);
+		if (!pMonitor) {
+			ASSERT("Failed to obtain monitor!");
+			return Rect();
+		}
+		gdk_monitor_get_geometry(pMonitor, &rr);
+		return SCL(rr.x, rr.y, rr.width, rr.height);
+	}
+#endif
+	if (GdkBackend::IsWayland()) {
+		ASSERT("GTK Wayland backend not supported before 3.22 GTK version.");
+		return Rect();
+	}
 	gint x, y, width, height;
-	gdk_window_get_geometry(gdk_screen_get_root_window(gdk_screen_get_default()),
-                            &x, &y, &width, &height);
-    Rect r = SCL(x, y, width, height);
-	return r;
+	gdk_window_get_geometry(pRootWindow, &x, &y, &width, &height);
+    return SCL(x, y, width, height);
 }
 
 Rect Ctrl::GetPrimaryWorkArea()
 {
 	GuiLock __;
 #if GTK_CHECK_VERSION(3, 22, 0)
+	if (GdkBackend::IsWayland()) {
+		// NOTE: WorkArea on Wayland is not available... Window manager decides where to put
+		// windows.
+		return GetVirtualScreenArea();
+	}
 	GdkRectangle rr;
-	gdk_monitor_get_workarea(gdk_display_get_primary_monitor(gdk_display_get_default()), &rr);
+	auto* display = gdk_display_get_default();
+	gdk_monitor_get_workarea(gdk_display_get_primary_monitor(display), &rr);
 	return SCL(rr.x, rr.y, rr.width, rr.height);
 #else
 	static Rect r;
@@ -384,16 +427,28 @@ void WakeUpGuiThread();
 void Ctrl::WndInvalidateRect(const Rect& r)
 {
 	GuiLock __;
-	LLOG("WndInvalidateRect " << r);
+	
+	Rect nr = r;
+	if (top && utop->csd->IsEnable()) {
+		gint x, y;
+		gdk_window_get_origin(gtk_widget_get_window(utop->drawing_area), &x, &y);
+		
+		nr.left += x;
+		nr.top += y;
+			
+		nr.right += x;
+		nr.bottom += y;
+	}
+	
 	Rect rr;
 	if(scale > 1) {
-		rr.left = r.left / 2;
-		rr.top = r.top / 2;
-		rr.right = (r.right + 1) / 2;
-		rr.bottom = (r.bottom + 1) / 2;
+		rr.left = nr.left / 2;
+		rr.top = nr.top / 2;
+		rr.right = (nr.right + 1) / 2;
+		rr.bottom = (nr.bottom + 1) / 2;
 	}
 	else
-		rr = r;
+		rr = nr;
 
 	// as gtk3 dropped thread locking, we need to push invalid rectangles onto main loop
 	for(Win& win : wins) {
diff --git a/uppsrc/CtrlCore/GtkX11Util.cpp b/uppsrc/CtrlCore/GtkX11Util.cpp
index 9250827b9..af18398c1 100644
--- a/uppsrc/CtrlCore/GtkX11Util.cpp
+++ b/uppsrc/CtrlCore/GtkX11Util.cpp
@@ -1,17 +1,14 @@
-#include "CtrlCore.h"
+#include <CtrlCore/CtrlCore.h>
 
 #ifdef GUI_GTK
-
 #ifdef GDK_WINDOWING_X11
 
-namespace Upp {
-
 #define Time        XTime
 #define Font        XFont
-#define Display     XDisplay
 #define Picture     XPicture
 
 #ifndef PLATFORM_OPENBSD // avoid warning
+#undef CurrentTime
 #define CurrentTime XCurrentTime
 #endif
 
@@ -20,13 +17,14 @@ namespace Upp {
 #undef Picture
 #undef Time
 #undef Font
-#undef Display
 
 #ifndef PLATFORM_OPENBSD // avoid warning
 #undef CurrentTime
 #endif
 
-XDisplay *Xdisplay()
+namespace Upp {
+
+_XDisplay *Xdisplay()
 {
 	return GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
 }
@@ -89,6 +87,9 @@ Atom XAtom(const char *name)
 
 Vector<int> GetPropertyInts(GdkWindow *w, const char *property)
 {
+	if (GdkBackend::IsWayland())
+		return {}; // Not supported on Wayland...
+	
 	GuiLock __;
 	Vector<int> result;
 	String p = GetProperty(GDK_WINDOW_XID(w), XAtom(property), AnyPropertyType);
@@ -114,6 +115,9 @@ dword X11mods(dword key)
 
 int Ctrl::RegisterSystemHotKey(dword key, Function<void ()> cb)
 {
+	if (GdkBackend::IsWayland())
+		return -1; // Not supported on Wayland...
+	
 	GuiLock __;
 	ASSERT(key >= K_DELTA);
 	gdk_x11_display_error_trap_push(gdk_display_get_default());
@@ -142,6 +146,9 @@ int Ctrl::RegisterSystemHotKey(dword key, Function<void ()> cb)
 
 void Ctrl::UnregisterSystemHotKey(int id)
 {
+	if (GdkBackend::IsWayland())
+		return; // Not supported on Wayland...
+	
 	GuiLock __;
 	if(id >= 0 && id < hotkey.GetCount() && hotkey[id]) {
 		gdk_x11_display_error_trap_push(gdk_display_get_default());
@@ -158,6 +165,9 @@ void Ctrl::UnregisterSystemHotKey(int id)
 
 GdkFilterReturn Ctrl::RootKeyFilter(GdkXEvent *xevent, GdkEvent *Xevent, gpointer data)
 {
+	if (GdkBackend::IsWayland())
+		return GDK_FILTER_CONTINUE; // Not supported on Wayland...
+	
 	XEvent *event = (XEvent *)xevent;
 	if(event->type == KeyPress)
 		for(int i = 0; i < hotkey.GetCount(); i++)
@@ -172,5 +182,4 @@ GdkFilterReturn Ctrl::RootKeyFilter(GdkXEvent *xevent, GdkEvent *Xevent, gpointe
 }
 
 #endif
-
 #endif
diff --git a/uppsrc/CtrlCore/X11App.cpp b/uppsrc/CtrlCore/X11App.cpp
index f613b9792..cbb891f6d 100644
--- a/uppsrc/CtrlCore/X11App.cpp
+++ b/uppsrc/CtrlCore/X11App.cpp
@@ -420,7 +420,7 @@ void Ctrl::InitX11(const char *display)
 		_NET_Supported().Add(nets[i]);
 
 	Font::SetDefaultFont(Arial(12));
-
+	
 	ReSkin();
 
 	GUI_GlobalStyle_Write(GUISTYLE_XP);
diff --git a/uppsrc/ide/About.cpp b/uppsrc/ide/About.cpp
index 7fcddc30d..d6a44ac69 100644
--- a/uppsrc/ide/About.cpp
+++ b/uppsrc/ide/About.cpp
@@ -72,7 +72,7 @@ String SplashCtrl::GenerateVersionInfo(bool qtf, bool about)
 #endif
 
 #ifdef GUI_GTK
-	h << " Gtk";
+	h << " Gtk::" << ToString(GdkBackend::Get());
 #endif
 #ifdef FLATPAK
 	h << " Flatpak";
diff --git a/uppsrc/ide/ide.upp b/uppsrc/ide/ide.upp
index 16bd4de88..b15678ec4 100644
--- a/uppsrc/ide/ide.upp
+++ b/uppsrc/ide/ide.upp
@@ -134,6 +134,7 @@ mainconfig
 	"" = "GUI PEAKMEM",
 	"" = "GUI HEAPLOG",
 	"" = "GUI X11",
+	"" = "GUI GTK WAYLAND",
 	"" = "GUI DEBUGCODE";
 
 custom() "",