diff --git a/onionshare/onion.py b/onionshare/onion.py
index 02f062fb..a3aee7a5 100644
--- a/onionshare/onion.py
+++ b/onionshare/onion.py
@@ -375,6 +375,17 @@ class Onion(object):
             # ephemeral stealth onion services are not supported
             self.supports_stealth = False
 
+
+    def is_authenticated(self):
+        """
+        Returns True if the Tor connection is still working, or False otherwise.
+        """
+        if self.c is not None:
+            return self.c.is_authenticated()
+        else:
+            return False
+
+
     def start_onion_service(self, port):
         """
         Start a onion service on port 80, pointing to the given port, and
diff --git a/onionshare_gui/onionshare_gui.py b/onionshare_gui/onionshare_gui.py
index 71a4843a..c056a32d 100644
--- a/onionshare_gui/onionshare_gui.py
+++ b/onionshare_gui/onionshare_gui.py
@@ -130,23 +130,25 @@ class OnionShareGui(QtWidgets.QMainWindow):
         self.setCentralWidget(central_widget)
         self.show()
 
-        # Check for requests frequently
-        self.timer = QtCore.QTimer()
-        self.timer.timeout.connect(self.check_for_requests)
-        self.timer.start(500)
-
         # Always start with focus on file selection
         self.file_selection.setFocus()
 
         # The server isn't active yet
         self.set_server_active(False)
 
+        # Create the timer
+        self.timer = QtCore.QTimer()
+        self.timer.timeout.connect(self.check_for_requests)
+
         # Start the "Connecting to Tor" dialog, which calls onion.connect()
         tor_con = TorConnectionDialog(self.qtapp, self.settings, self.onion)
         tor_con.canceled.connect(self._tor_connection_canceled)
         tor_con.open_settings.connect(self._tor_connection_open_settings)
         tor_con.start()
 
+        # Start the timer
+        self.timer.start(500)
+
         # After connecting to Tor, check for updates
         self.check_for_updates()
 
@@ -219,6 +221,17 @@ class OnionShareGui(QtWidgets.QMainWindow):
         def reload_settings():
             common.log('OnionShareGui', 'open_settings', 'settings have changed, reloading')
             self.settings.load()
+            # We might've stopped the main requests timer if a Tor connection failed.
+            # If we've reloaded settings, we probably succeeded in obtaining a new
+            # connection. If so, restart the timer.
+            if self.onion.is_authenticated():
+                if not self.timer.isActive():
+                    self.timer.start(500)
+                # If there were some files listed for sharing, we should be ok to
+                # re-enable the 'Start Sharing' button now.
+                if self.server_status.file_selection.get_num_files() > 0:
+                    self.server_status.server_button.setEnabled(True)
+                self.status_bar.clearMessage()
 
         d = SettingsDialog(self.onion, self.qtapp, self.config)
         d.settings_saved.connect(reload_settings)
@@ -398,6 +411,16 @@ class OnionShareGui(QtWidgets.QMainWindow):
         """
         self.update()
 
+        # Have we lost connection to Tor somehow?
+        if not self.onion.is_authenticated():
+            self.timer.stop()
+            if self.server_status.status != self.server_status.STATUS_STOPPED:
+                self.server_status.stop_server()
+            self.server_status.server_button.setEnabled(False)
+            self.status_bar.showMessage(strings._('gui_tor_connection_lost', True))
+            if self.systemTray.supportsMessages() and self.settings.get('systray_notifications'):
+                self.systemTray.showMessage(strings._('gui_tor_connection_lost', True), strings._('gui_tor_connection_error_settings', True))
+
         # scroll to the bottom of the dl progress bar log pane
         # if a new download has been added
         if self.new_download:
diff --git a/onionshare_gui/settings_dialog.py b/onionshare_gui/settings_dialog.py
index b9534511..6542a8d5 100644
--- a/onionshare_gui/settings_dialog.py
+++ b/onionshare_gui/settings_dialog.py
@@ -461,7 +461,8 @@ class SettingsDialog(QtWidgets.QDialog):
         # If Tor isn't connected, or if Tor settings have changed, Reinitialize
         # the Onion object
         reboot_onion = False
-        if self.onion.connected_to_tor:
+        if self.onion.is_authenticated():
+            common.log('SettingsDialog', 'save_clicked', 'Connected to Tor')
             def changed(s1, s2, keys):
                 """
                 Compare the Settings objects s1 and s2 and return true if any values
@@ -480,6 +481,7 @@ class SettingsDialog(QtWidgets.QDialog):
                 reboot_onion = True
 
         else:
+            common.log('SettingsDialog', 'save_clicked', 'Not connected to Tor')
             # Tor isn't connected, so try connecting
             reboot_onion = True
 
@@ -494,7 +496,7 @@ class SettingsDialog(QtWidgets.QDialog):
 
             common.log('SettingsDialog', 'save_clicked', 'Onion done rebooting, connected to Tor: {}'.format(self.onion.connected_to_tor))
 
-            if self.onion.connected_to_tor and not tor_con.wasCanceled():
+            if self.onion.is_authenticated() and not tor_con.wasCanceled():
                 self.settings_saved.emit()
                 self.close()
 
@@ -507,7 +509,7 @@ class SettingsDialog(QtWidgets.QDialog):
         Cancel button clicked.
         """
         common.log('SettingsDialog', 'cancel_clicked')
-        if not self.onion.connected_to_tor:
+        if not self.onion.is_authenticated():
             Alert(strings._('gui_tor_connection_canceled', True), QtWidgets.QMessageBox.Warning)
             sys.exit()
         else:
@@ -562,7 +564,7 @@ class SettingsDialog(QtWidgets.QDialog):
         common.log('SettingsDialog', 'closeEvent')
 
         # On close, if Tor isn't connected, then quit OnionShare altogether
-        if not self.onion.connected_to_tor:
+        if not self.onion.is_authenticated():
             common.log('SettingsDialog', 'closeEvent', 'Closing while not connected to Tor')
 
             # Wait 1ms for the event loop to finish, then quit
diff --git a/onionshare_gui/tor_connection_dialog.py b/onionshare_gui/tor_connection_dialog.py
index fa4c7860..dc472725 100644
--- a/onionshare_gui/tor_connection_dialog.py
+++ b/onionshare_gui/tor_connection_dialog.py
@@ -64,7 +64,7 @@ class TorConnectionDialog(QtWidgets.QProgressDialog):
         t.error_connecting_to_tor.connect(self._error_connecting_to_tor)
         t.start()
 
-        # The main thread needs to remain active, and checkign for Qt events,
+        # The main thread needs to remain active, and checking for Qt events,
         # until the thread is finished. Otherwise it won't be able to handle
         # accepting signals.
         self.active = True
@@ -86,6 +86,7 @@ class TorConnectionDialog(QtWidgets.QProgressDialog):
     def _canceled_connecting_to_tor(self):
         common.log('TorConnectionDialog', '_canceled_connecting_to_tor')
         self.active = False
+        self.onion.cleanup()
 
         # Cancel connecting to Tor
         QtCore.QTimer.singleShot(1, self.cancel)
diff --git a/share/locale/en.json b/share/locale/en.json
index 0756843e..abd734c9 100644
--- a/share/locale/en.json
+++ b/share/locale/en.json
@@ -119,6 +119,7 @@
     "gui_tor_connection_ask_quit": "Quit",
     "gui_tor_connection_error_settings": "Try adjusting how OnionShare connects to the Tor network in Settings.",
     "gui_tor_connection_canceled": "OnionShare cannot connect to Tor.\n\nMake sure you're connected to the internet, then re-open OnionShare to configure the Tor connection.",
+    "gui_tor_connection_lost": "Disconnected from Tor.",
     "gui_server_started_after_timeout": "The server started after your chosen auto-timeout.\nPlease start a new share.",
     "gui_server_timeout_expired": "The chosen timeout has already expired.\nPlease update the timeout and then you may start sharing.",
     "share_via_onionshare": "Share via OnionShare"