diff --git a/testing/web-platform/tests/url/resources/setters_tests.json b/testing/web-platform/tests/url/resources/setters_tests.json
index db217da23d55..d06fb2cfe629 100644
--- a/testing/web-platform/tests/url/resources/setters_tests.json
+++ b/testing/web-platform/tests/url/resources/setters_tests.json
@@ -1324,6 +1324,27 @@
                 "hostname": "test",
                 "port": "12"
             }
+        },
+        {
+            "comment": "Drop /. from path",
+            "href": "non-spec:/.//p",
+            "new_value": "h",
+            "expected": {
+                "href": "non-spec://h//p",
+                "host": "h",
+                "hostname": "h",
+                "pathname": "//p"
+            }
+        },
+        {
+            "href": "non-spec:/.//p",
+            "new_value": "",
+            "expected": {
+                "href": "non-spec:////p",
+                "host": "",
+                "hostname": "",
+                "pathname": "//p"
+            }
         }
     ],
     "port": [
@@ -1672,6 +1693,40 @@
                 "href": "file:///",
                 "pathname": "/"
             }
+        },
+        {
+            "comment": "Serialize /. in path",
+            "href": "non-spec:/",
+            "new_value": "/.//p",
+            "expected": {
+                "href": "non-spec:/.//p",
+                "pathname": "//p"
+            }
+        },
+        {
+            "href": "non-spec:/",
+            "new_value": "/..//p",
+            "expected": {
+                "href": "non-spec:/.//p",
+                "pathname": "//p"
+            }
+        },
+        {
+            "href": "non-spec:/",
+            "new_value": "//p",
+            "expected": {
+                "href": "non-spec:/.//p",
+                "pathname": "//p"
+            }
+        },
+        {
+            "comment": "Drop /. from path",
+            "href": "non-spec:/.//",
+            "new_value": "p",
+            "expected": {
+                "href": "non-spec:/p",
+                "pathname": "/p"
+            }
         }
     ],
     "search": [
diff --git a/testing/web-platform/tests/url/resources/urltestdata.json b/testing/web-platform/tests/url/resources/urltestdata.json
index bc79426526c1..76a8b3a015dc 100644
--- a/testing/web-platform/tests/url/resources/urltestdata.json
+++ b/testing/web-platform/tests/url/resources/urltestdata.json
@@ -6445,6 +6445,190 @@
     "search": "",
     "hash": ""
   },
+  "Serialize /. in path",
+  {
+    "input": "non-spec:/.//",
+    "base": "about:blank",
+    "href": "non-spec:/.//",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "non-spec:/..//",
+    "base": "about:blank",
+    "href": "non-spec:/.//",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "non-spec:/a/..//",
+    "base": "about:blank",
+    "href": "non-spec:/.//",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "non-spec:/.//path",
+    "base": "about:blank",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "non-spec:/..//path",
+    "base": "about:blank",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "non-spec:/a/..//path",
+    "base": "about:blank",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "/.//path",
+    "base": "non-spec:/p",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "/..//path",
+    "base": "non-spec:/p",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "..//path",
+    "base": "non-spec:/p",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "a/..//path",
+    "base": "non-spec:/p",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "",
+    "base": "non-spec:/..//p",
+    "href": "non-spec:/.//p",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//p",
+    "search": "",
+    "hash": ""
+  },
+  {
+    "input": "path",
+    "base": "non-spec:/..//p",
+    "href": "non-spec:/.//path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "//path",
+    "search": "",
+    "hash": ""
+  },
+  "Do not serialize /. in path",
+  {
+    "input": "../path",
+    "base": "non-spec:/.//p",
+    "href": "non-spec:/path",
+    "protocol": "non-spec:",
+    "username": "",
+    "password": "",
+    "host": "",
+    "hostname": "",
+    "port": "",
+    "pathname": "/path",
+    "search": "",
+    "hash": ""
+  },
   "# percent encoded hosts in non-special-URLs",
   {
     "input": "non-special://%E2%80%A0/",