diff --git a/src/calibre/gui2/icon_theme.py b/src/calibre/gui2/icon_theme.py
index 299bc225fe..2d0c3976f8 100644
--- a/src/calibre/gui2/icon_theme.py
+++ b/src/calibre/gui2/icon_theme.py
@@ -595,7 +595,8 @@ class ChooseTheme(Dialog):
         v.addStretch(), v.addWidget(pi, 0, Qt.AlignCenter)
         self.wait_msg = m = QLabel(self)
         v.addWidget(m, 0, Qt.AlignCenter), v.addStretch()
-        m.setStyleSheet('QLabel { font-size: 40px; font-weight: bold }')
+        f = m.font()
+        f.setBold(True), f.setPointSize(28), m.setFont(f)
         self.start_spinner()
 
         l.addWidget(c)
diff --git a/src/calibre/gui2/open_with.py b/src/calibre/gui2/open_with.py
index fa57141ef6..f3c0251e2c 100644
--- a/src/calibre/gui2/open_with.py
+++ b/src/calibre/gui2/open_with.py
@@ -244,7 +244,8 @@ class ChooseProgram(Dialog):  # {{{
         self.pi = pi = ProgressIndicator(self, 256)
         l.addStretch(1), l.addWidget(pi, alignment=Qt.AlignHCenter), l.addSpacing(10)
         w.la = la = QLabel(_('Gathering data, please wait...'))
-        la.setStyleSheet('QLabel { font-size: 30pt; font-weight: bold }')
+        f = la.font()
+        f.setBold(True), f.setPointSize(28), la.setFont(f)
         l.addWidget(la, alignment=Qt.AlignHCenter), l.addStretch(1)
         s.addWidget(w)
 
diff --git a/src/calibre/gui2/progress_indicator/__init__.py b/src/calibre/gui2/progress_indicator/__init__.py
index aba7861b07..3c1328fd3e 100644
--- a/src/calibre/gui2/progress_indicator/__init__.py
+++ b/src/calibre/gui2/progress_indicator/__init__.py
@@ -126,7 +126,9 @@ class WaitPanel(QWidget):
         self.start, self.stop = self.spinner.start, self.spinner.stop
         l.addStretch(), l.addWidget(self.spinner, 0, Qt.AlignCenter)
         self.la = QLabel(msg)
-        self.la.setStyleSheet('QLabel { font-size: 40px; font-weight: bold }')
+        f = self.la.font()
+        f.setPointSize(28)
+        self.la.setFont(f)
         l.addWidget(self.la, 0, Qt.AlignCenter), l.addStretch()
 
     @property
diff --git a/src/calibre/gui2/toc/main.py b/src/calibre/gui2/toc/main.py
index f4f5d356d1..f5c225b03b 100644
--- a/src/calibre/gui2/toc/main.py
+++ b/src/calibre/gui2/toc/main.py
@@ -884,7 +884,8 @@ class TOCEditor(QDialog):  # {{{
         ll.addWidget(pi, alignment=Qt.AlignHCenter|Qt.AlignCenter)
         la = self.wait_label = QLabel(_('Loading %s, please wait...')%t)
         la.setWordWrap(True)
-        la.setStyleSheet('QLabel { font-size: 20pt }')
+        f = la.font()
+        f.setPointSize(20), la.setFont(f)
         ll.addWidget(la, alignment=Qt.AlignHCenter|Qt.AlignTop)
         self.toc_view = TOCView(self, self.prefs)
         self.toc_view.add_new_item.connect(self.add_new_item)