diff --git a/testsuite/reftests/Makefile.am b/testsuite/reftests/Makefile.am
index fef107586d..b0422ed4b1 100644
--- a/testsuite/reftests/Makefile.am
+++ b/testsuite/reftests/Makefile.am
@@ -221,6 +221,9 @@ testdata = \
 	grid-spacing3.css \
 	grid-spacing3.ref.ui \
 	grid-spacing3.ui \
+	gtk-icontheme-sizing.css \
+	gtk-icontheme-sizing.ref.ui \
+	gtk-icontheme-sizing.ui \
 	icon-shadow-no-transform.css \
 	icon-shadow-no-transform.ref.ui \
 	icon-shadow-no-transform.ui \
diff --git a/testsuite/reftests/gtk-icontheme-sizing.css b/testsuite/reftests/gtk-icontheme-sizing.css
new file mode 100644
index 0000000000..083669d512
--- /dev/null
+++ b/testsuite/reftests/gtk-icontheme-sizing.css
@@ -0,0 +1,3 @@
+GtkBox {
+  background-image: -gtk-icontheme("pan-down-symbolic");
+}
diff --git a/testsuite/reftests/gtk-icontheme-sizing.ref.ui b/testsuite/reftests/gtk-icontheme-sizing.ref.ui
new file mode 100644
index 0000000000..7e7861d3cf
--- /dev/null
+++ b/testsuite/reftests/gtk-icontheme-sizing.ref.ui
@@ -0,0 +1,18 @@
+<?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="can_focus">False</property>
+    <property name="type">popup</property>
+    <child>
+      <object class="GtkImage" id="image1">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="pixel_size">100</property>
+        <property name="icon_name">pan-down-symbolic</property>
+        <property name="icon_size">0</property>
+      </object>
+    </child>
+  </object>
+</interface>
diff --git a/testsuite/reftests/gtk-icontheme-sizing.ui b/testsuite/reftests/gtk-icontheme-sizing.ui
new file mode 100644
index 0000000000..0d0015ec3b
--- /dev/null
+++ b/testsuite/reftests/gtk-icontheme-sizing.ui
@@ -0,0 +1,21 @@
+<?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">100</property>
+    <property name="height_request">100</property>
+    <property name="can_focus">False</property>
+    <property name="type">popup</property>
+    <child>
+      <object class="GtkBox" id="box1">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="orientation">vertical</property>
+        <child>
+          <placeholder/>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>