diff --git a/src/calibre/gui2/preferences/look_feel.py b/src/calibre/gui2/preferences/look_feel.py
index 469eaf35cb..db993a0424 100644
--- a/src/calibre/gui2/preferences/look_feel.py
+++ b/src/calibre/gui2/preferences/look_feel.py
@@ -220,6 +220,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.cover_grid_open_cache.clicked.connect(self.open_cg_cache)
         self.cover_grid_smaller_cover.clicked.connect(partial(self.resize_cover, True))
         self.cover_grid_larger_cover.clicked.connect(partial(self.resize_cover, False))
+        self.cover_grid_reset_size.clicked.connect(self.cg_reset_size)
         self.opt_cover_grid_disk_cache_size.setMinimum(self.gui.grid_view.thumbnail_cache.min_disk_cache)
         self.opt_cover_grid_disk_cache_size.setMaximum(self.gui.grid_view.thumbnail_cache.min_disk_cache * 100)
         self.opt_cover_grid_width.valueChanged.connect(self.update_aspect_ratio)
@@ -250,6 +251,10 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.opt_cover_grid_height.setValue(cval)
         self.opt_cover_grid_width.setValue(cval * ar)
 
+    def cg_reset_size(self):
+        self.opt_cover_grid_width.setValue(0)
+        self.opt_cover_grid_height.setValue(0)
+
     def initialize(self):
         ConfigWidgetBase.initialize(self)
         font = gprefs['font']
diff --git a/src/calibre/gui2/preferences/look_feel.ui b/src/calibre/gui2/preferences/look_feel.ui
index 45874a095f..92e2581ab0 100644
--- a/src/calibre/gui2/preferences/look_feel.ui
+++ b/src/calibre/gui2/preferences/look_feel.ui
@@ -367,6 +367,13 @@
           <string>Cover size</string>
          </property>
          <layout class="QGridLayout" name="gridLayout_4">
+          <item row="3" column="0" colspan="5">
+           <widget class="QLabel" name="cover_grid_aspect_ratio">
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
           <item row="1" column="0">
            <widget class="QLabel" name="label_11">
             <property name="text">
@@ -449,7 +456,7 @@ A value of zero means calculate automatically.</string>
             </property>
            </widget>
           </item>
-          <item row="1" column="3">
+          <item row="1" column="4">
            <spacer name="horizontalSpacer_4">
             <property name="orientation">
              <enum>Qt::Horizontal</enum>
@@ -462,7 +469,7 @@ A value of zero means calculate automatically.</string>
             </property>
            </spacer>
           </item>
-          <item row="0" column="0" colspan="4">
+          <item row="0" column="0" colspan="5">
            <widget class="QLabel" name="label_20">
             <property name="text">
              <string>By default, calibre chooses a cover size based on your computer's screen size. You can change the cover size here:</string>
@@ -472,10 +479,13 @@ A value of zero means calculate automatically.</string>
             </property>
            </widget>
           </item>
-          <item row="3" column="0" colspan="4">
-           <widget class="QLabel" name="cover_grid_aspect_ratio">
+          <item row="1" column="3" rowspan="2">
+           <widget class="QPushButton" name="cover_grid_reset_size">
+            <property name="toolTip">
+             <string>Reset size to automatic</string>
+            </property>
             <property name="text">
-             <string/>
+             <string>&amp;Reset size</string>
             </property>
            </widget>
           </item>