diff --git a/testsuite/reftests/Makefile.am b/testsuite/reftests/Makefile.am
index 5592f7a82f..cd005233cc 100644
--- a/testsuite/reftests/Makefile.am
+++ b/testsuite/reftests/Makefile.am
@@ -180,6 +180,9 @@ testdata = \
 	box-shadow-spread.css \
 	box-shadow-spread.ref.ui \
 	box-shadow-spread.ui \
+	box-shadow-changes-modify-clip.css \
+	box-shadow-changes-modify-clip.ref.ui \
+	box-shadow-changes-modify-clip.ui \
 	button-wrapping.ui \
 	button-wrapping.ref.ui \
 	cellrenderer-pixbuf-stock-rtl.css \
diff --git a/testsuite/reftests/box-shadow-changes-modify-clip.css b/testsuite/reftests/box-shadow-changes-modify-clip.css
new file mode 100644
index 0000000000..22ac11ca7f
--- /dev/null
+++ b/testsuite/reftests/box-shadow-changes-modify-clip.css
@@ -0,0 +1,19 @@
+@import "reset-to-defaults.css";
+
+@keyframes foo {
+  0% { box-shadow: 20px 20px tomato; }
+  100% { box-shadow: 20px 20px tomato; }
+}
+
+label {
+  font-size: 40px;
+  animation-name: foo;
+  animation-duration: 100s;
+  animation-timing-function: linear;
+  animation-delay: 1ms;
+}
+
+.reference {
+  animation: initial;
+  box-shadow: 20px 20px tomato;
+}
diff --git a/testsuite/reftests/box-shadow-changes-modify-clip.ref.ui b/testsuite/reftests/box-shadow-changes-modify-clip.ref.ui
new file mode 100644
index 0000000000..42a62bc250
--- /dev/null
+++ b/testsuite/reftests/box-shadow-changes-modify-clip.ref.ui
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.18.1 -->
+<interface>
+  <requires lib="gtk+" version="3.12"/>
+  <object class="GtkWindow" id="window1">
+    <property name="width_request">500</property>
+    <property name="height_request">100</property>
+    <property name="can_focus">False</property>
+    <property name="type">popup</property>
+    <child>
+      <object class="GtkLabel" id="label1">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="halign">center</property>
+        <property name="valign">center</property>
+        <property name="label" translatable="yes">Hello World</property>
+        <style>
+          <class name="reference"/>
+        </style>
+      </object>
+    </child>
+  </object>
+</interface>
diff --git a/testsuite/reftests/box-shadow-changes-modify-clip.ui b/testsuite/reftests/box-shadow-changes-modify-clip.ui
new file mode 100644
index 0000000000..3acad7e636
--- /dev/null
+++ b/testsuite/reftests/box-shadow-changes-modify-clip.ui
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.18.1 -->
+<interface>
+  <requires lib="gtk+" version="3.12"/>
+  <object class="GtkWindow" id="window1">
+    <property name="width_request">500</property>
+    <property name="height_request">100</property>
+    <property name="can_focus">False</property>
+    <property name="type">popup</property>
+    <signal name="map" handler="reftest:inhibit_for_3_frames" swapped="no"/>
+    <child>
+      <object class="GtkBox" id="box2">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="halign">center</property>
+        <property name="valign">center</property>
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkLabel" id="label1">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+            <property name="label" translatable="yes">Hello World</property>
+            <signal name="map" handler="reftest:add_reference_class_if_no_animation" swapped="no"/>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>