diff --git a/gui/qt/main_window.py b/gui/qt/main_window.py
index 3f96b84bc..336bec78b 100644
--- a/gui/qt/main_window.py
+++ b/gui/qt/main_window.py
@@ -269,7 +269,7 @@ class ElectrumWindow(QMainWindow, PrintError):
         self.update_account_selector()
         # update menus
         self.new_account_menu.setVisible(self.wallet.can_create_accounts())
-        self.private_keys_menu.setEnabled(not self.wallet.is_watching_only())
+        self.export_menu.setEnabled(not self.wallet.is_watching_only())
         self.password_menu.setEnabled(self.wallet.can_change_password())
         self.seed_menu.setEnabled(self.wallet.has_seed())
         self.mpk_menu.setEnabled(self.wallet.is_deterministic())
@@ -2009,10 +2009,8 @@ class ElectrumWindow(QMainWindow, PrintError):
             self.show_message(str(e))
             return
 
-        d = QDialog(self)
+        d = WindowModalDialog(self, _("Private key"))
         d.setMinimumSize(600, 200)
-        d.setModal(1)
-        d.setWindowTitle(_("Private key"))
         vbox = QVBoxLayout()
         vbox.addWidget( QLabel(_("Address") + ': ' + address))
         vbox.addWidget( QLabel(_("Private key") + ':'))
@@ -2457,12 +2455,11 @@ class ElectrumWindow(QMainWindow, PrintError):
 
 
     def sweep_key_dialog(self):
-        d = QDialog(self)
-        d.setWindowTitle(_('Sweep private keys'))
+        d = WindowModalDialog(self, title=_('Sweep private keys'))
         d.setMinimumSize(600, 300)
 
         vbox = QVBoxLayout(d)
-        vbox.addWidget(QLabel(_("Enter private keys")))
+        vbox.addWidget(QLabel(_("Enter private keys:")))
 
         keys_e = QTextEdit()
         keys_e.setTabChangesFocus(True)
@@ -2493,6 +2490,10 @@ class ElectrumWindow(QMainWindow, PrintError):
         if not d.exec_():
             return
 
+        if self.wallet.is_watching_only():
+            if not self.question(_("Warning: this wallet is watching only.  You will be UNABLE to spend the swept funds directly.  Continue only if you have access to the private keys in another way.\n\nAre you SURE you want to sweep?")):
+                return
+
         fee = self.wallet.fee_per_kb(self.config)
         tx = Transaction.sweep(get_pk(), self.network, get_address(), fee)
         if not tx:
diff --git a/gui/qt/util.py b/gui/qt/util.py
index 9ceaf11f8..039ab9bd7 100644
--- a/gui/qt/util.py
+++ b/gui/qt/util.py
@@ -192,6 +192,14 @@ class CancelButton(QPushButton):
         QPushButton.__init__(self, label or _("Cancel"))
         self.clicked.connect(dialog.reject)
 
+class WindowModalDialog(QDialog):
+    '''Handy wrapper; window modal dialogs are better for our multi-window
+    daemon model as other wallet windows can still be accessed.'''
+    def __init__(self, parent, title=None):
+        QDialog.__init__(self, parent)
+        self.setWindowModality(Qt.WindowModal)
+        if title:
+            self.setWindowTitle(title)
 
 def line_dialog(parent, title, label, ok_label, default=None):
     dialog = QDialog(parent)