diff --git a/coretk/coretk/dialogs/canvassizeandscale.py b/coretk/coretk/dialogs/canvassizeandscale.py
index f25dfdd6..fe4c3b62 100644
--- a/coretk/coretk/dialogs/canvassizeandscale.py
+++ b/coretk/coretk/dialogs/canvassizeandscale.py
@@ -187,5 +187,8 @@ class SizeAndScaleDialog(Dialog):
             location_config["lon"] = location.lon
             location_config["alt"] = location.alt
             location_config["scale"] = location.scale
+            preferences = self.app.guiconfig["preferences"]
+            preferences["width"] = width
+            preferences["height"] = height
             self.app.save_config()
         self.destroy()
diff --git a/coretk/coretk/dialogs/preferences.py b/coretk/coretk/dialogs/preferences.py
index 11903d2d..7298f727 100644
--- a/coretk/coretk/dialogs/preferences.py
+++ b/coretk/coretk/dialogs/preferences.py
@@ -14,8 +14,6 @@ class PreferencesDialog(Dialog):
         self.theme = tk.StringVar(value=preferences["theme"])
         self.terminal = tk.StringVar(value=preferences["terminal"])
         self.gui3d = tk.StringVar(value=preferences["gui3d"])
-        self.width = tk.StringVar(value=preferences["width"])
-        self.height = tk.StringVar(value=preferences["height"])
         self.draw()
 
     def draw(self):
@@ -60,16 +58,6 @@ class PreferencesDialog(Dialog):
         entry = ttk.Entry(frame, textvariable=self.gui3d)
         entry.grid(row=3, column=1, sticky="ew")
 
-        label = ttk.Label(frame, text="Canvas width (in pixel)")
-        label.grid(row=4, column=0, pady=2, padx=2, sticky="w")
-        entry = ttk.Entry(frame, textvariable=self.width)
-        entry.grid(row=4, column=1, sticky="ew")
-
-        label = ttk.Label(frame, text="Canvas height (in pixel)")
-        label.grid(row=5, column=0, pady=2, padx=2, sticky="w")
-        entry = ttk.Entry(frame, textvariable=self.height)
-        entry.grid(row=5, column=1, sticky="ew")
-
     def draw_buttons(self):
         frame = ttk.Frame(self.top)
         frame.grid(sticky="ew")
@@ -93,7 +81,5 @@ class PreferencesDialog(Dialog):
         preferences["editor"] = self.editor.get()
         preferences["gui3d"] = self.gui3d.get()
         preferences["theme"] = self.theme.get()
-        preferences["width"] = self.width.get()
-        preferences["height"] = self.height.get()
         self.app.save_config()
         self.destroy()