diff --git a/src/calibre/gui2/tweak_book/diff/main.py b/src/calibre/gui2/tweak_book/diff/main.py
index 04c9c3fb4f..a4ba8622b8 100644
--- a/src/calibre/gui2/tweak_book/diff/main.py
+++ b/src/calibre/gui2/tweak_book/diff/main.py
@@ -156,14 +156,14 @@ class Diff(Dialog):
 
         r = l.rowCount()
         self.bn = b = QToolButton(self)
-        b.setIcon(QIcon(I('arrow-down.png')))
+        b.setIcon(QIcon(I('back.png')))
         b.clicked.connect(partial(self.view.next_change, 1))
         b.setToolTip(_('Go to next change'))
         b.setText(_('&Next change')), b.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
         l.addWidget(b, r, l.columnCount(), 1, 1)
 
         self.bp = b = QToolButton(self)
-        b.setIcon(QIcon(I('arrow-up.png')))
+        b.setIcon(QIcon(I('forward.png')))
         b.clicked.connect(partial(self.view.next_change, -1))
         b.setToolTip(_('Go to previous change'))
         b.setText(_('&Previous change')), b.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
diff --git a/src/calibre/gui2/tweak_book/diff/view.py b/src/calibre/gui2/tweak_book/diff/view.py
index 9aba99a7a2..d01be290e8 100644
--- a/src/calibre/gui2/tweak_book/diff/view.py
+++ b/src/calibre/gui2/tweak_book/diff/view.py
@@ -250,8 +250,8 @@ class TextBrowser(PlainTextEdit):  # {{{
             r = ev.rect()
             if block.isVisible() and bottom >= r.top():
                 text = unicode(self.line_number_map.get(num, ''))
-                is_start = num in change_starts
-                if is_start and text != '-':
+                is_start = text != '-' and num in change_starts
+                if is_start:
                     painter.save()
                     f = QFont(self.font())
                     f.setBold(True)