diff --git a/PySimpleGUI.py b/PySimpleGUI.py
index 2f69a2be..18c6001f 100644
--- a/PySimpleGUI.py
+++ b/PySimpleGUI.py
@@ -2406,7 +2406,7 @@ class ErrorElement(Element):
 # ------------------------------------------------------------------------- #
 class Window:
 
-    def __init__(self, title, default_element_size=DEFAULT_ELEMENT_SIZE, default_button_element_size = (None, None), auto_size_text=None, auto_size_buttons=None, location=(None, None), button_color=None, font=None, progress_bar_color=(None, None), background_color=None, border_depth=None, auto_close=False, auto_close_duration=DEFAULT_AUTOCLOSE_TIME, icon=DEFAULT_WINDOW_ICON, force_toplevel = False, return_keyboard_events=False, use_default_focus=True, text_justification=None, no_titlebar=False, grab_anywhere=False, keep_on_top=False):
+    def __init__(self, title, default_element_size=DEFAULT_ELEMENT_SIZE, default_button_element_size = (None, None), auto_size_text=None, auto_size_buttons=None, location=(None, None), button_color=None, font=None, progress_bar_color=(None, None), background_color=None, border_depth=None, auto_close=False, auto_close_duration=DEFAULT_AUTOCLOSE_TIME, icon=DEFAULT_WINDOW_ICON, force_toplevel = False, return_keyboard_events=False, use_default_focus=True, text_justification=None, no_titlebar=False, grab_anywhere=False, keep_on_top=False, resizable=False):
         '''
         Window
         :param title:
@@ -2470,6 +2470,7 @@ class Window:
         self.GrabAnywhere = grab_anywhere
         self.KeepOnTop = keep_on_top
         self.ForceTopLevel = force_toplevel
+        self.Resizable = resizable
 
     # ------------------------- Add ONE Row to Form ------------------------- #
     def AddRow(self, *args):
@@ -4015,6 +4016,9 @@ def StartupTK(my_flex_form):
         root.bind("<ButtonRelease-1>", my_flex_form.StopMove)
         root.bind("<B1-Motion>", my_flex_form.OnMotion)
 
+    if not my_flex_form.Resizable:
+        root.resizable(False,False)
+
     if my_flex_form.KeepOnTop:
         root.wm_attributes("-topmost", 1)