diff --git a/gui/commands.py b/gui/commands.py
index 3048ce5..2cb6451 100644
--- a/gui/commands.py
+++ b/gui/commands.py
@@ -41,8 +41,7 @@ class GuiSourceCommand(gdb.Command):
 
     def invoke(self, arg, from_tty):
         self.dont_repeat()
-        gui.startup.start_gtk()
-        gui.startup.send_to_gtk(gui.source.SourceWindow)
+        gui.source.SourceWindow()
 
 class GuiLogWindowCommand(gdb.Command):
     """Create a new log window.
@@ -63,7 +62,6 @@ class GuiLogWindowCommand(gdb.Command):
 
     def invoke(self, arg, from_tty):
         self.dont_repeat()
-        gui.startup.start_gtk()
         window = gui.logwindow.LogWindow()
         print "Created log window %d; now the default" % window.number
 
@@ -136,8 +134,6 @@ class GuiDisplayCommand(gdb.Command):
 
     def invoke(self, arg, from_tty):
         self.dont_repeat()
-        # FIXME: perhaps Toplevel should be calling startup_gtk
-        gui.startup.start_gtk()
         gui.display.DisplayWindow(arg)
 
     def complete(self, text, word):
diff --git a/gui/source.py b/gui/source.py
index 8d04949..073ea00 100644
--- a/gui/source.py
+++ b/gui/source.py
@@ -176,7 +176,10 @@ class SourceWindow(Toplevel):
 
     def __init__(self):
         super(SourceWindow, self).__init__()
+        gui.startup.send_to_gtk(self._initialize)
 
+    @in_gtk_thread
+    def _initialize(self):
         self.frame = None
 
         self.do_step = Invoker("step")
diff --git a/gui/toplevel.py b/gui/toplevel.py
index 45064f0..e7116ab 100644
--- a/gui/toplevel.py
+++ b/gui/toplevel.py
@@ -21,6 +21,7 @@ import threading
 
 class _ToplevelState(object):
     def __init__(self):
+        gui.startup.start_gtk()
         # This lock must be held when using the other globals here.
         self.toplevel_lock = threading.Lock()
         self.next_toplevel = 1