diff --git a/src/dialogs.py b/src/dialogs.py
index 16ecc60f3..bf2f37943 100644
--- a/src/dialogs.py
+++ b/src/dialogs.py
@@ -718,6 +718,19 @@ _('You can not join a group chat unless you are connected.')).get_response()
 		elif room and server:
 			self.xml.get_widget('join_button').grab_focus()
 
+		self._empty_required_widgets = []
+		self._server_entry = self.xml.get_widget('server_entry')
+		self._room_entry = self.xml.get_widget('room_entry')
+		self._nickname_entry = self.xml.get_widget('nickname_entry')
+		if not self._server_entry.get_text():
+			self._empty_required_widgets.append(self._server_entry)
+		if not self._room_entry.get_text():
+			self._empty_required_widgets.append(self._room_entry)
+		if not self._nickname_entry.get_text():
+			self._empty_required_widgets.append(self._nickname_entry)
+		if len(self._empty_required_widgets):
+			self.xml.get_widget('join_button').set_sensitive(False)
+
 		self.window.show_all()
 
 	def on_join_groupchat_window_destroy(self, widget):
@@ -729,6 +742,16 @@ _('You can not join a group chat unless you are connected.')).get_response()
 		if event.keyval == gtk.keysyms.Escape: # ESCAPE
 			widget.destroy()
 
+	def on_required_entry_changed(self, widget):
+		if not widget.get_text():
+			self._empty_required_widgets.append(widget)
+			self.xml.get_widget('join_button').set_sensitive(False)
+		else:
+			if widget in self._empty_required_widgets:
+				self._empty_required_widgets.remove(widget)
+				if len(self._empty_required_widgets) == 0:
+					self.xml.get_widget('join_button').set_sensitive(True)
+
 	def on_room_entry_key_press_event(self, widget, event):
 		# Check for pressed @ and jump to server_entry if found
 		if event.keyval == gtk.keysyms.at:
diff --git a/src/gtkgui.glade b/src/gtkgui.glade
index 22375c7f1..b47e79f21 100644
--- a/src/gtkgui.glade
+++ b/src/gtkgui.glade
@@ -9434,6 +9434,7 @@ Custom</property>
 	      <property name="invisible_char">*</property>
 	      <property name="activates_default">True</property>
 	      <signal name="key_press_event" handler="on_server_entry_key_press_event" last_modification_time="Fri, 25 Nov 2005 22:09:39 GMT"/>
+	      <signal name="changed" handler="on_required_entry_changed" last_modification_time="Sat, 14 Jan 2006 21:51:55 GMT"/>
 	    </widget>
 	    <packing>
 	      <property name="left_attach">1</property>
@@ -9457,6 +9458,7 @@ Custom</property>
 	      <property name="invisible_char">*</property>
 	      <property name="activates_default">True</property>
 	      <signal name="key_press_event" handler="on_room_entry_key_press_event" last_modification_time="Fri, 25 Nov 2005 22:07:30 GMT"/>
+	      <signal name="changed" handler="on_required_entry_changed" last_modification_time="Sat, 14 Jan 2006 21:51:39 GMT"/>
 	    </widget>
 	    <packing>
 	      <property name="left_attach">1</property>
@@ -9478,6 +9480,7 @@ Custom</property>
 	      <property name="has_frame">True</property>
 	      <property name="invisible_char">*</property>
 	      <property name="activates_default">True</property>
+	      <signal name="changed" handler="on_required_entry_changed" last_modification_time="Sat, 14 Jan 2006 21:51:24 GMT"/>
 	    </widget>
 	    <packing>
 	      <property name="left_attach">1</property>