diff --git a/src/calibre/gui2/tweak_book/boss.py b/src/calibre/gui2/tweak_book/boss.py
index 4b72227178..49fd3cbbce 100644
--- a/src/calibre/gui2/tweak_book/boss.py
+++ b/src/calibre/gui2/tweak_book/boss.py
@@ -387,8 +387,9 @@ class Boss(QObject):
         d.bb = QDialogButtonBox(QDialogButtonBox.Close)
         if changed:
             b = d.b = d.bb.addButton(_('See what &changed'), d.bb.AcceptRole)
-            b.setIcon(QIcon(I('diff.png')))
+            b.setIcon(QIcon(I('diff.png'))), b.setAutoDefault(False)
             b.clicked.connect(partial(self.show_current_diff, allow_revert=True))
+        d.bb.button(d.bb.Close).setDefault(True)
         d.l.addWidget(d.bb)
         d.bb.rejected.connect(d.reject)
         d.bb.accepted.connect(d.accept)
diff --git a/src/calibre/gui2/tweak_book/diff/main.py b/src/calibre/gui2/tweak_book/diff/main.py
index 65f3db3180..0ac4f12873 100644
--- a/src/calibre/gui2/tweak_book/diff/main.py
+++ b/src/calibre/gui2/tweak_book/diff/main.py
@@ -274,9 +274,10 @@ class Diff(Dialog):
 
         self.bb.setStandardButtons(self.bb.Close)
         if self.revert_button_msg is not None:
-            self.rvb = b = self.bb.addButton(self.revert_button_msg, self.bb.RejectRole)
-            b.setIcon(QIcon(I('edit-undo.png')))
+            self.rvb = b = self.bb.addButton(self.revert_button_msg, self.bb.ActionRole)
+            b.setIcon(QIcon(I('edit-undo.png'))), b.setAutoDefault(False)
             b.clicked.connect(self.revert_requested)
+            b.clicked.connect(self.reject)
         self.bb.button(self.bb.Close).setDefault(True)
         self.hl.addWidget(self.bb, r)