diff --git a/src/xpra/client/client_tray.py b/src/xpra/client/client_tray.py
index 8a306ef07a..cd7f6b5003 100644
--- a/src/xpra/client/client_tray.py
+++ b/src/xpra/client/client_tray.py
@@ -127,7 +127,7 @@ def new_backing(self, w, h):
     def update_metadata(self, metadata):
         log("%s.update_metadata(%s)", self, metadata)
 
-    def update_icon(self, width, height, coding, data):
+    def update_icon(self, img):
         #this is the window icon... not the tray icon!
         pass
 
diff --git a/src/xpra/client/client_window_base.py b/src/xpra/client/client_window_base.py
index cf9b4104cb..053dc4de5d 100644
--- a/src/xpra/client/client_window_base.py
+++ b/src/xpra/client/client_window_base.py
@@ -153,24 +153,24 @@ def reset_icon(self):
         if current_icon:
             self.update_icon(*current_icon)
 
-    def update_icon(self, width, height, coding, data):
-        raise Exception("override me!")
+    def update_icon(self, img):
+        raise NotImplementedError("override me!")
 
     def is_realized(self):
-        raise Exception("override me!")
+        raise NotImplementedError("override me!")
 
     def apply_transient_for(self, wid):
-        raise Exception("override me!")
+        raise NotImplementedError("override me!")
 
     def paint_spinner(self, context, area):
-        raise Exception("override me!")
+        raise NotImplementedError("override me!")
 
     def _pointer_modifiers(self, event):
-        raise Exception("override me!")
+        raise NotImplementedError("override me!")
 
 
     def xget_u32_property(self, target, name):
-        raise Exception("override me!")
+        raise NotImplementedError("override me!")
 
 
     def is_OR(self):
diff --git a/src/xpra/client/gtk_base/gtk_client_window_base.py b/src/xpra/client/gtk_base/gtk_client_window_base.py
index bb2eb619a8..e1a650851a 100644
--- a/src/xpra/client/gtk_base/gtk_client_window_base.py
+++ b/src/xpra/client/gtk_base/gtk_client_window_base.py
@@ -25,7 +25,7 @@
 grablog = Logger("grab")
 
 
-from xpra.os_util import memoryview_to_bytes, bytestostr, WIN32, OSX, POSIX, PYTHON3
+from xpra.os_util import bytestostr, WIN32, OSX, POSIX, PYTHON3
 from xpra.util import (AdHocStruct, typedict, envint, envbool, nonl,
                        WORKSPACE_UNSET, WORKSPACE_ALL, WORKSPACE_NAMES, MOVERESIZE_DIRECTION_STRING, SOURCE_INDICATION_STRING,
                        MOVERESIZE_CANCEL,
@@ -41,7 +41,6 @@
 from xpra.gtk_common.keymap import KEY_TRANSLATIONS
 from xpra.client.client_window_base import ClientWindowBase
 from xpra.platform.gui import set_fullscreen_monitors, set_shaded
-from xpra.codecs.argb.argb import unpremultiply_argb, bgra_to_rgba    #@UnresolvedImport
 from xpra.platform.gui import add_window_hooks, remove_window_hooks
 
 gtk     = import_gtk()
@@ -83,6 +82,7 @@
 BREAK_MOVERESIZE = os.environ.get("XPRA_BREAK_MOVERESIZE", "Escape").split(",")
 MOVERESIZE_X11 = envbool("XPRA_MOVERESIZE_X11", POSIX)
 
+ICON_OVERLAY = envbool("XPRA_ICON_OVERLAY", True)
 OSX_FOCUS_WORKAROUND = envbool("XPRA_OSX_FOCUS_WORKAROUND", True)
 SAVE_WINDOW_ICONS = envbool("XPRA_SAVE_WINDOW_ICONS", False)
 UNDECORATED_TRANSIENT_IS_OR = envint("XPRA_UNDECORATED_TRANSIENT_IS_OR", 1)
@@ -1519,22 +1519,11 @@ def do_scroll_event(self, event):
             self._button_action(button_mapping, event, False)
 
 
-    def update_icon(self, width, height, coding, data):
-        self._current_icon = (width, height, coding, data)
-        coding = bytestostr(coding)
-        iconlog("%s.update_icon(%s, %s, %s, %s bytes)", self, width, height, coding, len(data))
-        if coding == "premult_argb32":            #we usually cannot do in-place and this is not performance critical
-            data = unpremultiply_argb(data)
-            rgba = memoryview_to_bytes(memoryview(bgra_to_rgba(data)))
-            pixbuf = get_pixbuf_from_data(rgba, True, width, height, width*4)
-        else:
-            loader = PixbufLoader()
-            loader.write(data)
-            loader.close()
-            pixbuf = loader.get_pixbuf()
+    def update_icon(self, img):
+        self._current_icon = img
+        has_alpha = img.mode=="RGBA"
+        width, height = img.size
+        rowstride = width * (3+int(has_alpha))
+        pixbuf = get_pixbuf_from_data(img.tobytes(), has_alpha, width, height, rowstride)
         iconlog("%s.set_icon(%s)", self, pixbuf)
         self.set_icon(pixbuf)
-        if SAVE_WINDOW_ICONS:
-            filename = "client-window-%i-icon-%i.png" % (self._id, int(time.time()))
-            pixbuf.save(filename, "png")
-            iconlog("client window icon saved to %s", filename)
diff --git a/src/xpra/client/ui_client_base.py b/src/xpra/client/ui_client_base.py
index 5a530858ad..e2ff75e2d6 100644
--- a/src/xpra/client/ui_client_base.py
+++ b/src/xpra/client/ui_client_base.py
@@ -63,7 +63,7 @@
 from xpra.net.compression import Compressed
 from xpra.child_reaper import reaper_cleanup
 from xpra.make_thread import make_thread
-from xpra.os_util import BytesIOClass, Queue, platform_name, get_machine_id, get_user_uuid, bytestostr, monotonic_time, strtobytes, OSX, POSIX
+from xpra.os_util import BytesIOClass, Queue, platform_name, get_machine_id, get_user_uuid, bytestostr, monotonic_time, strtobytes, memoryview_to_bytes, OSX, POSIX
 from xpra.util import nonl, std, iround, envint, envfloat, envbool, AtomicInteger, log_screen_sizes, typedict, updict, csv, engs, CLIENT_EXIT, XPRA_APP_ID
 from xpra.version_util import get_version_info_full, get_platform_info
 try:
@@ -111,6 +111,9 @@ def add_legacy_names(codecs):
 
 TRAY_DELAY = envint("XPRA_TRAY_DELAY", 0)
 
+ICON_OVERLAY = envbool("XPRA_ICON_OVERLAY", True)
+SAVE_WINDOW_ICONS = envbool("XPRA_SAVE_WINDOW_ICONS", False)
+
 WEBCAM_ALLOW_VIRTUAL = envbool("XPRA_WEBCAM_ALLOW_VIRTUAL", False)
 WEBCAM_TARGET_FPS = max(1, min(50, envint("XPRA_WEBCAM_FPS", 20)))
 
@@ -3440,11 +3443,46 @@ def _process_window_metadata(self, packet):
             window.update_metadata(metadata)
 
     def _process_window_icon(self, packet):
-        wid, w, h, pixel_format, data = packet[1:6]
+        wid, w, h, coding, data = packet[1:6]
+        img = self._window_icon_image(wid, w, h, coding, data)
         window = self._id_to_window.get(wid)
-        iconlog("_process_window_icon(%s, %s, %s, %s, %s bytes) window=%s", wid, w, h, pixel_format, len(data), window)
-        if window:
-            window.update_icon(w, h, pixel_format, data)
+        iconlog("_process_window_icon(%s, %s, %s, %s, %s bytes) image=%s, window=%s", wid, w, h, coding, len(data), img, window)
+        if window and img:
+            window.update_icon(img)
+
+    def _window_icon_image(self, wid, width, height, coding, data):
+        #convert the data into a pillow image,
+        #adding the icon overlay (if enabled)
+        PIL = get_codec("PIL")
+        assert PIL.Image, "PIL.Image not found"
+        coding = bytestostr(coding)
+        iconlog("%s.update_icon(%s, %s, %s, %s bytes)", self, width, height, coding, len(data))
+        if coding == "premult_argb32":            #we usually cannot do in-place and this is not performance critical
+            from xpra.codecs.argb.argb import unpremultiply_argb    #@UnresolvedImport
+            data = unpremultiply_argb(data)
+            rowstride = width*4
+            img = PIL.Image.frombytes("RGBA", (width,height), memoryview_to_bytes(data), "raw", "BGRA", rowstride, 1)
+            has_alpha = True
+        else:
+            buf = BytesIOClass(data)
+            img = PIL.Image.open(buf)
+            assert img.mode in ("RGB", "RGBA"), "invalid image mode: %s" % img.mode
+            has_alpha = img.mode=="RGBA"
+            rowstride = width * (3+int(has_alpha))
+        if ICON_OVERLAY:
+            xpra_icon_filename = get_icon_filename("xpra")
+            xpra_icon = PIL.Image.open(xpra_icon_filename)
+            half = xpra_icon.resize((width//2, height//2))
+            xpra_corner = PIL.Image.new("RGBA", (width, height))
+            xpra_corner.paste(half, (width//2, height//2, width, height))
+            composite = PIL.Image.alpha_composite(img, xpra_corner)
+            img = composite
+        if SAVE_WINDOW_ICONS:
+            filename = "client-window-%i-icon-%i.png" % (wid, int(time.time()))
+            img.save(filename, "png")
+            iconlog("client window icon saved to %s", filename)
+        return img
+        
 
     def _process_configure_override_redirect(self, packet):
         wid, x, y, w, h = packet[1:6]
diff --git a/src/xpra/server/window/window_source.py b/src/xpra/server/window/window_source.py
index 07d1e229d1..1f0fb25d38 100644
--- a/src/xpra/server/window/window_source.py
+++ b/src/xpra/server/window/window_source.py
@@ -33,6 +33,9 @@
 
 MAX_PIXELS_PREFER_RGB = envint("XPRA_MAX_PIXELS_PREFER_RGB", 4096)
 
+ARGB_ICONS = envbool("XPRA_ARGB_ICONS", True)
+PNG_ICONS = envbool("XPRA_PNG_ICONS", True)
+
 DELTA = envbool("XPRA_DELTA", True)
 MIN_DELTA_SIZE = envint("XPRA_MIN_DELTA_SIZE", 1024)
 MAX_DELTA_SIZE = envint("XPRA_MAX_DELTA_SIZE", 32768)
@@ -614,8 +617,8 @@ def compress_and_send_window_icon(self):
         #use png if supported and if "premult_argb32" is not supported by the client (ie: html5)
         #or if we must downscale it (bigger than what the client is willing to deal with),
         #or if we want to save window icons
-        has_png = PIL and ("png" in self.window_icon_encodings)
-        has_premult = "premult_argb32" in self.window_icon_encodings
+        has_png = PIL and PNG_ICONS and ("png" in self.window_icon_encodings)
+        has_premult = ARGB_ICONS and "premult_argb32" in self.window_icon_encodings
         use_png = has_png and (SAVE_WINDOW_ICONS or w>max_w or h>max_h or w*h>=1024 or (not has_premult) or (pixel_format!="BGRA"))
         iconlog("compress_and_send_window_icon: %sx%s (max-size=%s, standard-size=%s), sending as png=%s, has_png=%s, has_premult=%s, pixel_format=%s", w, h, self.window_icon_max_size, self.window_icon_size, use_png, has_png, has_premult, pixel_format)
         if use_png: