diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset-2.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset-2.html
new file mode 100644
index 0000000000000..1bfd3fc00ae94
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset-2.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="windows-1250">
+<title>JSON modules: UTF-8 decoding</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script type="module">
+  import json from "../serve-with-content-type.py?fn=json-module/utf-8.json" assert { type: "json"};
+  test(() => {
+    assert_equals(json.data, "śćążź");
+  }, "JSON module should be loaded as utf-8 even though document's encoding is windows-1250");
+</script>
+<script type="module">
+  import json from "../serve-with-content-type.py?fn=json-module/windows-1250.json&ct=text/json%3Bcharset=windows-1250" assert { type: "json"};
+  test(() => {
+    assert_not_equals(json.data, "śćążź",
+                    'Should be decoded as UTF-8');
+  }, "JSON module should be loaded as utf-8 even if it is encoded in windows-1250 and served with a windows-1250 charset response header, and this document's encoding is windows-1250");
+</script>
\ No newline at end of file
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset.html
new file mode 100644
index 0000000000000..de30de8c2e5d4
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/charset.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>JSON modules: UTF-8 decoding</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script type="module" onerror="unreachable()">
+  import json from "../serve-with-content-type.py?fn=json-module/utf-8.json&ct=text/json%3Bcharset=utf-8" assert { type: "json"};
+  test(() => {
+    assert_equals(json.data, "śćążź");
+  }, "JSON module should be loaded as utf-8 when charset=utf8 is specified");
+</script>
+<script type="module" onerror="unreachable()">
+  import json from "../serve-with-content-type.py?fn=json-module/utf-8.json&ct=text/json%3Bcharset=shift-jis" assert { type: "json"};
+  test(() => {
+    assert_equals(json.data, "śćążź");
+  }, "JSON module should be loaded as utf-8 when charset=shift-jis is specified");
+</script>
+<script type="module" onerror="unreachable()">
+  import json from "../serve-with-content-type.py?fn=json-module/utf-8.json&ct=text/json%3Bcharset=windows-1252" assert { type: "json"};
+  test(() => {
+    assert_equals(json.data, "śćążź");
+  }, "JSON module should be loaded as utf-8 when charset=windows-1252 is specified");
+</script>
+<script type="module" onerror="unreachable()">
+  import json from "../serve-with-content-type.py?fn=json-module/utf-8.json&ct=text/json%3Bcharset=utf-7" assert { type: "json"};;
+  test(() => {
+    assert_equals(json.data, "śćążź");
+  }, "JSON module should be loaded as utf-8 when charset=utf-7 is specified");
+</script>
+<script type="module" onerror="unreachable()">
+  import json from "../serve-with-content-type.py?fn=json-module/windows-1250.json&ct=text/json%3Bcharset=windows-1250" assert { type: "json"};
+  test(() => {
+    assert_not_equals(json.data, "śćążź",
+                    'Should be decoded as UTF-8');
+  }, "JSON module should be loaded as utf-8 even if it is encoded in windows-1250 and served with a windows-1250 charset response header");
+</script>
\ No newline at end of file
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-matches.js b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-matches.js
new file mode 100644
index 0000000000000..969c90c2907cc
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-matches.js
@@ -0,0 +1,2 @@
+import json from "./data.json" assert { type: "json" };
+window.matchesLog.push(`integrity-matches,json:${json.answer}`);
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-mismatches.js b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-mismatches.js
new file mode 100644
index 0000000000000..3c88a98dbc551
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity-mismatches.js
@@ -0,0 +1,2 @@
+import json "./data.json" assert { type: "json" };
+window.mismatchesLog.push(`integrity-mismatches,json:${json.answer}`);
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity.html
new file mode 100644
index 0000000000000..68a794b973359
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/integrity.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>&lt;script> integrity=""</title>
+<link rel="help" href="https://html.spec.whatwg.org/multipage/#prepare-a-script">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+window.matchesLog = [];
+window.matchesEvents = [];
+
+window.mismatchesLog = [];
+window.mismatchesEvents = [];
+</script>
+<script type="module" src="integrity-matches.js" integrity="sha384-VmQQfGzBiLKdyzw4FA4kL4ohu4tyujV68ddgW1aN/1v3cBZNNBn2gDFdVQxfL7+a"  onload="window.matchesEvents.push('load');" onerror="window.matchesEvents.push('error')"></script>
+<script type="module" src="integrity-mismatches.js" integrity="sha384-doesnotmatch" onload="window.mismatchesEvents.push('load');" onerror="window.mismatchesEvents.push('error')"></script>
+
+<script type="module">
+test(() => {
+  assert_array_equals(window.matchesLog, ["integrity-matches,json:42"], "The module and its dependency must have executed");
+  assert_array_equals(window.matchesEvents, ["load"], "The load event must have fired");
+}, "The integrity attribute must be verified on the top-level of a module loading a JSON module and allow it to execute when it matches");
+
+test(() => {
+  assert_array_equals(window.mismatchesLog, [], "The module and its dependency must not have executed");
+  assert_array_equals(window.mismatchesEvents, ["error"], "The error event must have fired");
+}, "The integrity attribute must be verified on the top-level of a module loading a JSON module and not allow it to execute when there's a mismatch");
+</script>
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf-8.json b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf-8.json
new file mode 100644
index 0000000000000..088d98235873d
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf-8.json
@@ -0,0 +1,4 @@
+{
+  "data": "śćążź",
+  "comment": "The data above are five Polish letters, similar to scazz. It can be read correctly only with utf-8 encoding."
+}
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.json b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.json
deleted file mode 100644
index 7bb9edd2f79e8..0000000000000
--- a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "test": "…"
-}
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.tentative.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.tentative.html
deleted file mode 100644
index 24a6f109e1c58..0000000000000
--- a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/utf8.tentative.html
+++ /dev/null
@@ -1,36 +0,0 @@
-<!DOCTYPE html>
-<meta charset=utf-8>
-<title>JSON modules: UTF-8 decoding</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<div id=log></div>
-<script>
-function check(t, v) {
-  t.step(() => {
-    assert_equals(typeof v, "object");
-    assert_array_equals(Object.keys(v), ["test"]);
-    assert_equals(v.test, "\u2026");
-    t.done();
-  });
-}
-const t1 = async_test("utf-8");
-const t2 = async_test("shift-jis");
-const t3 = async_test("windows-1252");
-const t4 = async_test("utf-7");
-</script>
-<script type="module" onerror="t1.step(() => assert_unreached(event))">
-import v from "../serve-with-content-type.py?fn=json-module/utf8.json&ct=text/json%3Bcharset=utf-8" assert { type: "json"};
-check(t1, v);
-</script>
-<script type="module" onerror="t2.step(() => assert_unreached(event))">
-import v from "../serve-with-content-type.py?fn=json-module/utf8.json&ct=text/json%3Bcharset=shift-jis" assert { type: "json"};
-check(t2, v);
-</script>
-<script type="module" onerror="t3.step(() => assert_unreached(event))">
-import v from "../serve-with-content-type.py?fn=json-module/utf8.json&ct=text/json%3Bcharset=windows-1252" assert { type: "json"};
-check(t3, v);
-</script>
-<script type="module" onerror="t4.step(() => assert_unreached(event))">
-import v from "../serve-with-content-type.py?fn=json-module/utf8.json&ct=text/json%3Bcharset=utf-7" assert { type: "json"};;
-check(t4, v);
-</script>
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/valid-content-type.tentative.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/valid-content-type.tentative.html
index ff5953cb700ef..75d6b756a40eb 100644
--- a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/valid-content-type.tentative.html
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/valid-content-type.tentative.html
@@ -17,6 +17,8 @@
 const t2 = async_test("application/json");
 const t3 = async_test("text/html+json");
 const t4 = async_test("image/svg+json");
+const t5 = async_test("text/json;boundary=something");
+const t6 = async_test("text/json;foo=bar");
 </script>
 <script type="module" onerror="t1.step(() => assert_unreached(event))">
 import v from "../serve-with-content-type.py?fn=json-module/module.json&ct=text/json" assert { type: "json"};
@@ -34,3 +36,11 @@
 import v from "../serve-with-content-type.py?fn=json-module/module.json&ct=image/svg+json" assert { type: "json"};
 check(t4, v);
 </script>
+<script type="module" onerror="t5.step(() => assert_unreached(event))">
+import v from "../serve-with-content-type.py?fn=json-module/module.json&ct=text/json;boundary=something" assert { type: "json"};
+check(t5, v);
+</script>
+<script type="module" onerror="t6.step(() => assert_unreached(event))">
+import v from "../serve-with-content-type.py?fn=json-module/module.json&ct=text/json;foo=bar" assert { type: "json"};
+check(t6, v);
+</script>
\ No newline at end of file
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/windows-1250.json b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/windows-1250.json
new file mode 100644
index 0000000000000..490e752ce93c7
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/json-module/windows-1250.json
@@ -0,0 +1,4 @@
+{
+  "data": "�湿�",
+  "comment": "The data above are five Polish letters, similar to scazz. It can be read correctly only with windows1250 encoding."
+}
