diff --git a/testing/web-platform/meta/css/css-anchor-position/popover-implicit-anchor.tentative.html.ini b/testing/web-platform/meta/css/css-anchor-position/popover-implicit-anchor.tentative.html.ini
new file mode 100644
index 000000000000..9ea5d5857d0f
--- /dev/null
+++ b/testing/web-platform/meta/css/css-anchor-position/popover-implicit-anchor.tentative.html.ini
@@ -0,0 +1,3 @@
+[popover-implicit-anchor.tentative.html]
+  [Popover invokers form an implicit anchor reference]
+    expected: FAIL
diff --git a/testing/web-platform/meta/html/semantics/forms/the-select-element/customizable-select/select-inside-top-layer.tentative.html.ini b/testing/web-platform/meta/html/semantics/forms/the-select-element/customizable-select/select-inside-top-layer.tentative.html.ini
new file mode 100644
index 000000000000..b10edcc64d99
--- /dev/null
+++ b/testing/web-platform/meta/html/semantics/forms/the-select-element/customizable-select/select-inside-top-layer.tentative.html.ini
@@ -0,0 +1,12 @@
+[select-inside-top-layer.tentative.html]
+  [select can be nested inside a popover]
+    expected: FAIL
+
+  [a popover can be nested inside select]
+    expected: FAIL
+
+  [select can be nested inside a modal dialog]
+    expected: FAIL
+
+  [a modal dialog can be nested inside select]
+    expected: FAIL