diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80c3ace..3718015 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,20 @@
 All notable changes to this project are documented here. This project follows
 [Semantic Versioning](https://semver.org/).
 
+## [1.1.1]
+
+### Fixed
+
+- **expectJsonSchema actually validates now.** It was calling the validator with
+  its arguments swapped, so schema checks silently passed for most bodies. It now
+  validates the response body against the schema.
+- **Deep equality no longer reports false matches for Date / RegExp / Map / Set.**
+  `matches()` (used by `expectJson`, `expectBody`, `expectHeader`, `expectCookie`)
+  now delegates to the correct `isEqual`, so `expectJson(path, new Date(...))` and
+  similar comparisons are meaningful instead of always passing.
+- **The JSON-schema validator rejects `NaN`** for `type: "number"` (and therefore
+  for `minimum`/`maximum`), since JSON has no `NaN`.
+
 ## [1.1.0]
 
 ### Added
diff --git a/package.json b/package.json
index bd91aa9..994519b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "two-go",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "description": "Zero-dependency fluent service/API testing library: chainable HTTP requests, Jest-style + HTTP assertions, and a lodash-inspired utility belt. Works standalone or inside node:test, Jest, Vitest, and Mocha.",
   "type": "module",
   "main": "src/index.js",
diff --git a/src/assertions.js b/src/assertions.js
index 4886b23..4037684 100644
--- a/src/assertions.js
+++ b/src/assertions.js
@@ -1,5 +1,7 @@
 // Core assertion primitives shared by GoResponse and RequestBuilder.
-// These have no dependencies and are safe to use standalone.
+// Deep equality is delegated to isEqual from the utility belt so there is a
+// single, correct source of truth (it handles Date, RegExp, Map, Set, NaN).
+import { isEqual } from "./utils/lang.js";
 
 // Error thrown by every failing assertion. Carries the expected/actual values
 // so test runners (and humans) can inspect the mismatch.
@@ -37,7 +39,7 @@ export function resolvePath(obj, path) {
 // Flexible value matcher used by expectJson / expectHeader / expectBody.
 // - RegExp:   test against String(actual)
 // - function: treat as predicate, truthy return means match
-// - object/array: structural deepEqual
+// - object/array: deep equality (Date/RegExp/Map/Set aware via isEqual)
 // - primitive: strict ===
 export function matches(actual, expected) {
   if (expected instanceof RegExp) {
@@ -47,30 +49,11 @@ export function matches(actual, expected) {
     return Boolean(expected(actual));
   }
   if (expected !== null && typeof expected === "object") {
-    return deepEqual(actual, expected);
+    return isEqual(actual, expected);
   }
   return actual === expected;
 }
 
-// Recursive structural equality. Compares own enumerable keys.
-export function deepEqual(a, b) {
-  if (a === b) return true;
-
-  if (a === null || b === null) return false;
-  if (typeof a !== "object" || typeof b !== "object") return false;
-
-  const aIsArray = Array.isArray(a);
-  const bIsArray = Array.isArray(b);
-  if (aIsArray !== bIsArray) return false;
-
-  const aKeys = Object.keys(a);
-  const bKeys = Object.keys(b);
-  if (aKeys.length !== bKeys.length) return false;
-
-  for (const key of aKeys) {
-    if (!Object.prototype.hasOwnProperty.call(b, key)) return false;
-    if (!deepEqual(a[key], b[key])) return false;
-  }
-
-  return true;
-}
+// Deep structural equality. Kept as a named export for back-compat; it is the
+// same correct implementation used everywhere else.
+export { isEqual as deepEqual };
diff --git a/src/http-assertions.js b/src/http-assertions.js
index cebef8d..f7f06ce 100644
--- a/src/http-assertions.js
+++ b/src/http-assertions.js
@@ -190,7 +190,7 @@ const methods = {
 
   // Validate the parsed body against a schema, listing every error on failure.
   expectJsonSchema(schema) {
-    const result = validate(schema, this.body);
+    const result = validate(this.body, schema);
 
     // Support either a { valid, errors } result or a bare errors array.
     let valid;
diff --git a/src/schema.js b/src/schema.js
index dedcec7..c57260e 100644
--- a/src/schema.js
+++ b/src/schema.js
@@ -15,7 +15,8 @@ import {
 // Map of supported "type" keyword values to their predicate.
 const TYPE_CHECKS = {
   string: isString,
-  number: isNumber,
+  // JSON has no NaN/Infinity, so a "number" must be finite (rejects NaN).
+  number: (v) => isNumber(v) && Number.isFinite(v),
   integer: isInteger,
   boolean: isBoolean,
   object: isPlainObject,
diff --git a/test/unit/assertion-correctness.test.mjs b/test/unit/assertion-correctness.test.mjs
new file mode 100644
index 0000000..ced34f4
--- /dev/null
+++ b/test/unit/assertion-correctness.test.mjs
@@ -0,0 +1,28 @@
+// Regression tests for the Tier 0 false-pass fixes.
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { matches, deepEqual } from "../../src/assertions.js";
+import { validate } from "../../src/schema.js";
+
+test("matches no longer treats different Dates as equal", () => {
+  assert.equal(matches(new Date(0), new Date(1000)), false);
+  assert.equal(matches(new Date(1000), new Date(1000)), true);
+});
+
+test("matches distinguishes Maps, Sets, and RegExps", () => {
+  assert.equal(matches(new Map([["a", 1]]), new Map([["a", 2]])), false);
+  assert.equal(matches(new Set([1, 2]), new Set([1, 3])), false);
+  assert.equal(matches(/a/i, /b/i), false);
+  assert.equal(deepEqual(new Set([1, 2]), new Set([1, 2])), true);
+});
+
+test("plain object deep equality still works", () => {
+  assert.equal(matches({ a: 1, b: [2, 3] }, { a: 1, b: [2, 3] }), true);
+  assert.equal(matches({ a: 1 }, { a: 2 }), false);
+});
+
+test("schema validator rejects NaN for type number and range", () => {
+  assert.equal(validate(NaN, { type: "number" }).valid, false);
+  assert.equal(validate(NaN, { type: "number", minimum: 0, maximum: 10 }).valid, false);
+  assert.equal(validate(5, { type: "number", minimum: 0, maximum: 10 }).valid, true);
+});
diff --git a/test/unit/http-assertions.test.mjs b/test/unit/http-assertions.test.mjs
index 201e0fc..427195b 100644
--- a/test/unit/http-assertions.test.mjs
+++ b/test/unit/http-assertions.test.mjs
@@ -238,18 +238,29 @@ test("expectValue returns an expect() wrapper for chaining matchers", () => {
   );
 });
 
-test("expectJsonSchema passes when validation yields no errors", () => {
-  // validate(schema, body) is invoked internally; when the effective schema
-  // (the body) is not a plain object, validation short-circuits to valid.
-  const res = makeResponse({ body: "plain-text-body" });
-  assert.ok(res.expectJsonSchema({ type: "string" }));
+test("expectJsonSchema passes when the body matches the schema", () => {
+  const res = makeResponse({ body: { id: 1, name: "Ada" } });
+  assert.ok(
+    res.expectJsonSchema({
+      type: "object",
+      required: ["id"],
+      properties: { id: { type: "integer" }, name: { type: "string" } },
+    })
+  );
 });
 
-test("expectJsonSchema fails and lists errors when validation fails", () => {
-  // Here the body acts as the effective schema and the passed argument as the
-  // value, so a non-matching pair produces validation errors.
-  const res = makeResponse({ body: { type: "number" } });
-  assertFails(() => res.expectJsonSchema("not-a-number"), "GET", "/x");
+test("expectJsonSchema fails and lists errors when the body violates the schema", () => {
+  const res = makeResponse({ body: { id: "not-a-number" } });
+  assertFails(
+    () =>
+      res.expectJsonSchema({
+        type: "object",
+        required: ["id"],
+        properties: { id: { type: "integer" } },
+      }),
+    "GET",
+    "/x"
+  );
 });
 
 test("methods are installed as non-enumerable on the prototype and chain", () => {