diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 16c97ba626..1e4672360b 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -322,7 +322,7 @@ def question_dialog(parent, title, msg, det_msg='', show_copy_button=False,
         # Set skip_dialog_msg to a message displayed to the user
         skip_dialog_name=None, skip_dialog_msg=_('Show this confirmation again'),
         skip_dialog_skipped_value=True, skip_dialog_skip_precheck=True,
-        # Override icon (QIcon to be used as the icon for this dialog)
+        # Override icon (QIcon to be used as the icon for this dialog or string for I())
         override_icon=None,
         # Change the text/icons of the yes and no buttons.
         # The icons must be QIcon objects or strings for I()
diff --git a/src/calibre/gui2/dialogs/message_box.py b/src/calibre/gui2/dialogs/message_box.py
index df4fe4389b..fb1f62ea74 100644
--- a/src/calibre/gui2/dialogs/message_box.py
+++ b/src/calibre/gui2/dialogs/message_box.py
@@ -33,7 +33,7 @@ class MessageBox(QDialog):  # {{{
         la.setObjectName("icon_label")
         l.addWidget(la)
         self.msg = la = QLabel(self)
-        la.setWordWrap(True)
+        la.setWordWrap(True), la.setMinimumWidth(400)
         la.setOpenExternalLinks(True)
         la.setObjectName("msg")
         l.addWidget(la, 0, 1, 1, 1)
@@ -68,7 +68,7 @@ class MessageBox(QDialog):  # {{{
             icon = 'dialog_%s.png'%icon
             self.icon = QIcon(I(icon))
         else:
-            self.icon = q_icon
+            self.icon = q_icon if isinstance(q_icon, QIcon) else QIcon(I(q_icon))
         self.setup_ui()
 
         self.setWindowTitle(title)