--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -535905,17 +535905,17 @@
    "ba0a0f2eda2703c742dd71b3106a3c78da27e677",
    "support"
   ],
   "editing/data/insertorderedlist.js": [
    "9387d479a52fd5146d5d708eb1244250f3dd02b6",
    "support"
   ],
   "editing/data/insertparagraph.js": [
-   "5cc4cee5d1ba32775a3a940e11ce46215b276466",
+   "7e5061611c18e53d67329ebd32bc078bcce4c73d",
    "support"
   ],
   "editing/data/inserttext.js": [
    "be6f17c7af88382808ee574d9291fbc606ab7ec4",
    "support"
   ],
   "editing/data/insertunorderedlist.js": [
    "ed8c92ce7bc902a5125e082798ad9abfef469f18",

--- a/testing/web-platform/tests/editing/data/insertparagraph.js
+++ b/testing/web-platform/tests/editing/data/insertparagraph.js
@@ -1594,10 +1594,30 @@ var browserTests = [
     [["defaultparagraphseparator","div"],["insertparagraph",""]],
     "<div class=\"a\" id=\"x\"><p class=\"b\" id=\"y\">foo</p><p class=\"b\">{}bar</p></div>",
     [true,true],
     {"defaultparagraphseparator":[false,false,"p",false,false,"div"],"insertparagraph":[false,false,"",false,false,""]}],
 ["<div class=a id=x><p class=b id=y>foo[]bar</div>",
     [["defaultparagraphseparator","p"],["insertparagraph",""]],
     "<div class=\"a\" id=\"x\"><p class=\"b\" id=\"y\">foo</p><p class=\"b\">{}bar</p></div>",
     [true,true],
-    {"defaultparagraphseparator":[false,false,"div",false,false,"p"],"insertparagraph":[false,false,"",false,false,""]}]
+    {"defaultparagraphseparator":[false,false,"div",false,false,"p"],"insertparagraph":[false,false,"",false,false,""]}],
+["<div contenteditable=false><foo-bar contenteditable><p>foo[]bar</p></foo-bar></div>",
+    [["defaultparagraphseparator","div"],["insertparagraph",""]],
+    "<div contenteditable=\"false\"><foo-bar contenteditable=\"\"><p>foo</p><p>bar</p></foo-bar></div>",
+    [true,true],
+    {"defaultparagraphseparator":[false,false,"p",false,false,"div"],"insertparagraph":[false,false,"",false,false,""]}],
+["<div contenteditable=false><foo-bar contenteditable><p>foo[]bar</p></foo-bar></div>",
+    [["defaultparagraphseparator","p"],["insertparagraph",""]],
+    "<div contenteditable=\"false\"><foo-bar contenteditable=\"\"><p>foo</p><p>bar</p></foo-bar></div>",
+    [true,true],
+    {"defaultparagraphseparator":[false,false,"div",false,false,"p"],"insertparagraph":[false,false,"",false,false,""]}],
+["<div contenteditable=false><foo-bar contenteditable><div>foo[]bar</div></foo-bar></div>",
+    [["defaultparagraphseparator","div"],["insertparagraph",""]],
+    "<div contenteditable=\"false\"><foo-bar contenteditable=\"\"><div>foo</div><div>bar</div></foo-bar></div>",
+    [true,true],
+    {"defaultparagraphseparator":[false,false,"p",false,false,"div"],"insertparagraph":[false,false,"",false,false,""]}],
+["<div contenteditable=false><foo-bar contenteditable><div>foo[]bar</div></foo-bar></div>",
+    [["defaultparagraphseparator","p"],["insertparagraph",""]],
+    "<div contenteditable=\"false\"><foo-bar contenteditable=\"\"><div>foo</div><div>bar</div></foo-bar></div>",
+    [true,true],
+    {"defaultparagraphseparator":[false,false,"div",false,false,"p"],"insertparagraph":[false,false,"",false,false,""]}],
 ]