diff --git a/gui/qt/main_window.py b/gui/qt/main_window.py
index ea01cffd0..69f009f28 100644
--- a/gui/qt/main_window.py
+++ b/gui/qt/main_window.py
@@ -2269,25 +2269,38 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         private_keys = {}
         addresses = self.wallet.get_addresses()
         done = False
+        cancelled = False
         def privkeys_thread():
             for addr in addresses:
                 time.sleep(0.1)
-                if done:
+                if done or cancelled:
                     break
                 privkey = self.wallet.export_private_key(addr, password)[0]
                 private_keys[addr] = privkey
                 self.computing_privkeys_signal.emit()
-            self.computing_privkeys_signal.disconnect()
-            self.show_privkeys_signal.emit()
+            if not cancelled:
+                self.computing_privkeys_signal.disconnect()
+                self.show_privkeys_signal.emit()
 
         def show_privkeys():
             s = "\n".join( map( lambda x: x[0] + "\t"+ x[1], private_keys.items()))
             e.setText(s)
             b.setEnabled(True)
             self.show_privkeys_signal.disconnect()
+            nonlocal done
+            done = True
+
+        def on_dialog_closed(*args):
+            nonlocal done
+            nonlocal cancelled
+            if not done:
+                cancelled = True
+                self.computing_privkeys_signal.disconnect()
+                self.show_privkeys_signal.disconnect()
 
         self.computing_privkeys_signal.connect(lambda: e.setText("Please wait... %d/%d"%(len(private_keys),len(addresses))))
         self.show_privkeys_signal.connect(show_privkeys)
+        d.finished.connect(on_dialog_closed)
         threading.Thread(target=privkeys_thread).start()
 
         if not d.exec_():
diff --git a/plugins/ledger/ledger.py b/plugins/ledger/ledger.py
index 62ba23394..2d1a593c4 100644
--- a/plugins/ledger/ledger.py
+++ b/plugins/ledger/ledger.py
@@ -60,6 +60,21 @@ class Ledger_Client():
     def versiontuple(self, v):
         return tuple(map(int, (v.split("."))))
 
+    def test_pin_unlocked(func):
+        """Function decorator to test the Ledger for being unlocked, and if not,
+        raise a human-readable exception.
+        """
+        def catch_exception(self, *args, **kwargs):
+            try:
+                return func(self, *args, **kwargs)
+            except BTChipException as e:
+                if e.sw == 0x6982:
+                    raise Exception(_('Your Ledger is locked. Please unlock it.'))
+                else:
+                    raise
+        return catch_exception
+
+    @test_pin_unlocked
     def get_xpub(self, bip32_path, xtype):
         self.checkDevice()
         # bip32_path is of the form 44'/0'/1'
@@ -80,7 +95,7 @@ class Ledger_Client():
         if len(splitPath) > 1:
             prevPath = "/".join(splitPath[0:len(splitPath) - 1])
             nodeData = self.dongleObject.getWalletPublicKey(prevPath)
-            publicKey = compress_public_key(nodeData['publicKey'])#
+            publicKey = compress_public_key(nodeData['publicKey'])
             h = hashlib.new('ripemd160')
             h.update(hashlib.sha256(publicKey).digest())
             fingerprint = unpack(">I", h.digest()[0:4])[0]