diff --git a/src/xpra/client/gl/gtk3/gl_client_window.py b/src/xpra/client/gl/gtk3/gl_client_window.py
index 95dd6bb0e1..913b09ad35 100644
--- a/src/xpra/client/gl/gtk3/gl_client_window.py
+++ b/src/xpra/client/gl/gtk3/gl_client_window.py
@@ -8,6 +8,7 @@
 
 from xpra.client.gtk3.gtk3_client_window import GTK3ClientWindow
 from xpra.gtk_common.gtk_util import set_visual
+from xpra.util import typedict
 from xpra.log import Logger
 
 log = Logger("opengl", "window")
@@ -91,6 +92,11 @@ def new_backing(self, bw, bh):
         set_visual(widget, self._has_alpha)
         widget.show()
         self.init_widget_events(widget)
+        if self.drawing_area and self.size_constraints:
+            #apply min size to the drawing_area:
+            thints = typedict(self.size_constraints)
+            minsize = thints.intpair("minimum-size", (0, 0))
+            self.drawing_area.set_size_request(*minsize)
         self.add(widget)
         self.drawing_area = widget
         #maybe redundant?:
diff --git a/src/xpra/client/gtk3/gtk3_client_window.py b/src/xpra/client/gtk3/gtk3_client_window.py
index 540145a87b..cd4a93ebc4 100644
--- a/src/xpra/client/gtk3/gtk3_client_window.py
+++ b/src/xpra/client/gtk3/gtk3_client_window.py
@@ -77,7 +77,16 @@ def can_use_header_bar(self, metadata):
             return False
         if hbl in TRUE_OPTIONS:
             sc = metadata.dictget("size-constraints")
-            return sc is None
+            if sc is None:
+                return True
+            tsc = typedict(sc)
+            mins = tsc.intpair("minimum-size")
+            maxs = tsc.intpair("maximum-size")
+            if maxs and maxs!=(0, 0) and maxs!=mins:
+                return False
+            if tsc.intpair("increment", (0, 0))!=(0, 0):
+                return False
+            return True
         if hbl=="force":
             return True
         return False
@@ -175,6 +184,14 @@ def apply_geometry_hints(self, hints):
                         "min_aspect_ratio"  : "min_aspect",
                         "max_aspect_ratio"  : "max_aspect",
                          }
+        thints = typedict(hints)
+        if self.drawing_area:
+            #apply min size to the drawing_area:
+            #(for CSD mode, ie: headerbar)
+            minw = thints.intget("min_width", 0)
+            minh = thints.intget("min_width", 0)
+            self.drawing_area.set_size_request(minw, minh)
+
         geom = Gdk.Geometry()
         mask = 0
         for k,v in hints.items():
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 4ec7351a61..b152e0de78 100644
--- a/src/xpra/client/gtk_base/gtk_client_window_base.py
+++ b/src/xpra/client/gtk_base/gtk_client_window_base.py
@@ -218,6 +218,7 @@ def init_window(self, metadata):
     def init_drawing_area(self):
         widget = Gtk.DrawingArea()
         widget.set_app_paintable(True)
+        widget.set_size_request(*self._size)
         widget.show()
         self.drawing_area = widget
         self.init_widget_events(widget)
@@ -1687,6 +1688,11 @@ def do_map_event(self, event):
             if self._iconified:
                 self.deiconify()
             self.process_map_event()
+        #use the drawing area to enforce the minimum size:
+        #(as this also honoured correctly with CSD,
+        # whereas set_geometry_hints is not..)
+        minw, minh = self.size_constraints.intpair("minimum-size", (0, 0))
+        self.drawing_area.set_size_request(minw, minh)
 
     def process_map_event(self):
         x, y, w, h = self.get_drawing_area_geometry()