diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index e864d1fa024..fd5197b13a0 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -311,6 +311,7 @@ resolution=800x600 == viewport_percentage_vmin_vmax.html viewport_percentage_vmi
resolution=600x800 == viewport_percentage_vmin_vmax.html viewport_percentage_vmin_vmax_b.html
resolution=800x600 == viewport_percentage_vw_vh.html viewport_percentage_vw_vh_a.html
resolution=600x800 == viewport_percentage_vw_vh.html viewport_percentage_vw_vh_b.html
+experimental == viewport_rule.html viewport_rule_ref.html
== visibility_hidden.html visibility_hidden_ref.html
flaky_cpu == webgl-context/clearcolor.html webgl-context/clearcolor_ref.html
diff --git a/tests/ref/viewport_rule.html b/tests/ref/viewport_rule.html
new file mode 100644
index 00000000000..bccd08bb79d
--- /dev/null
+++ b/tests/ref/viewport_rule.html
@@ -0,0 +1,29 @@
+
+
+
+
+
+
+
+
+
diff --git a/tests/ref/viewport_rule_ref.html b/tests/ref/viewport_rule_ref.html
new file mode 100644
index 00000000000..2cd2b347d3f
--- /dev/null
+++ b/tests/ref/viewport_rule_ref.html
@@ -0,0 +1,24 @@
+
+
+
+
+
+
+
+
+