diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index 6e4d129eaf..a63fb2c8c6 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -185,6 +185,8 @@ class EbookViewer(MainWindow, Ui_EbookViewer):
         self.pos.setDecimals(1)
         self.pos.setSuffix('/'+_('Unknown')+'     ')
         self.pos.setMinimum(1.)
+        self.splitter.setCollapsible(0, False)
+        self.splitter.setCollapsible(1, False)
         self.pos.setMinimumWidth(150)
         self.tool_bar2.insertWidget(self.action_find_next, self.pos)
         self.reference = Reference()
@@ -1028,6 +1030,8 @@ class EbookViewer(MainWindow, Ui_EbookViewer):
         av = available_height() - 30
         if self.height() > av:
             self.resize(self.width(), av)
+        self.splitter.setCollapsible(0, False)
+        self.splitter.setCollapsible(1, False)
 
 def config(defaults=None):
     desc = _('Options to control the ebook viewer')
diff --git a/src/calibre/gui2/viewer/main.ui b/src/calibre/gui2/viewer/main.ui
index fe0fa62a79..ddc4cfb776 100644
--- a/src/calibre/gui2/viewer/main.ui
+++ b/src/calibre/gui2/viewer/main.ui
@@ -27,7 +27,14 @@
       <property name="childrenCollapsible">
        <bool>false</bool>
       </property>
-      <widget class="TOCView" name="toc"/>
+      <widget class="TOCView" name="toc">
+       <property name="minimumSize">
+        <size>
+         <width>150</width>
+         <height>0</height>
+        </size>
+       </property>
+      </widget>
       <widget class="QFrame" name="frame">
        <property name="frameShape">
         <enum>QFrame::StyledPanel</enum>