diff --git a/testsuite/reftests/meson.build b/testsuite/reftests/meson.build
index a50b8f84df..8df36fab93 100644
--- a/testsuite/reftests/meson.build
+++ b/testsuite/reftests/meson.build
@@ -439,6 +439,8 @@ testdata = [
   'window-default-size.ui',
   'window-height-for-width.ref.ui',
   'window-height-for-width.ui',
+  'window-show-contents-on-map.ref.ui',
+  'window-show-contents-on-map.ui',
 ]
 
 # These need to be fixed but the issue hasn't been tracked down.
diff --git a/testsuite/reftests/window-show-contents-on-map.ref.ui b/testsuite/reftests/window-show-contents-on-map.ref.ui
new file mode 100644
index 0000000000..f24540ed6b
--- /dev/null
+++ b/testsuite/reftests/window-show-contents-on-map.ref.ui
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkWindow" id="window1">
+    <property name="width_request">200</property>
+    <property name="height_request">200</property>
+    <property name="decorated">0</property>
+    <child>
+      <object class="GtkLabel" id="label1">
+        <property name="label" translatable="yes">This label is only shown when the window is mapped. So the window does its first size allocation without the label being visible and has to resize.</property>
+        <property name="wrap">1</property>
+        <property name="width_chars">20</property>
+        <property name="max_width_chars">20</property>
+      </object>
+    </child>
+  </object>
+</interface>
diff --git a/testsuite/reftests/window-show-contents-on-map.ui b/testsuite/reftests/window-show-contents-on-map.ui
new file mode 100644
index 0000000000..88e00d8e51
--- /dev/null
+++ b/testsuite/reftests/window-show-contents-on-map.ui
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkWindow" id="window1">
+    <property name="decorated">0</property>
+    <signal name="map" handler="gtk_widget_show" object="label1" after="yes" swapped="yes"/>
+    <child>
+      <object class="GtkLabel" id="label1">
+        <property name="visible">0</property>
+        <property name="label" translatable="yes">This label is only shown when the window is mapped. So the window does its first size allocation without the label being visible and has to resize.</property>
+        <property name="width_chars">20</property>
+        <property name="wrap">1</property>
+      </object>
+    </child>
+  </object>
+</interface>