diff --git a/src/calibre/gui2/dialogs/choose_library.py b/src/calibre/gui2/dialogs/choose_library.py
index bf1741cd87..32d45c6043 100644
--- a/src/calibre/gui2/dialogs/choose_library.py
+++ b/src/calibre/gui2/dialogs/choose_library.py
@@ -80,8 +80,10 @@ class ChooseLibrary(QDialog, Ui_Dialog):
             return error_dialog(self, _('No location'), _('No location selected'),
                     show=True)
         loc = os.path.abspath(text)
-        if not loc or not os.path.exists(loc) or not self.check_action(action,
-                loc):
+        if not loc or not os.path.exists(loc) or not os.path.isdir(loc):
+            return error_dialog(self, _('Bad location'),
+                    _('%s is not an existing folder')%loc, show=True)
+        if not self.check_action(action, loc):
             return
         QDialog.accept(self)
         self.location.save_history()