diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 92b3858..37c5f0b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -14,6 +14,7 @@ jobs:
     strategy:
       matrix:
         php: ['8.4', '8.5']
+        dependencies: [highest, lowest]
 
     steps:
       - uses: actions/checkout@v7
@@ -25,11 +26,17 @@ jobs:
           extensions: dom, mbstring
           tools: composer:v2
 
-      - name: Install dependencies
-        run: composer install
+      - name: Install dependencies (highest)
+        if: matrix.dependencies == 'highest'
+        run: composer update --no-interaction
+
+      - name: Install dependencies (lowest)
+        if: matrix.dependencies == 'lowest'
+        run: composer update --no-interaction --prefer-lowest --prefer-stable
 
       - name: Run tests
         run: ./vendor/bin/phpunit
 
       - name: Static analysis
+        if: matrix.dependencies == 'highest'
         run: ./vendor/bin/psalm --output-format=github --no-progress
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f6eb5e..6dac749 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,14 @@
 # Change Log
 All notable changes to this project will be documented in this file.
 
+## [v4.0.0](https://github.com/fivefilters/readability.php/releases/tag/v4.0.0)
+
+First stable release of the 4.0 series — a ground-up rewrite. This release includes **all changes from [v4.0.0-beta.1](https://github.com/fivefilters/readability.php/releases/tag/v4.0.0-beta.1) below** (see [UPGRADE.md](UPGRADE.md) for the 3.x → 4.0 migration guide), plus the following changes since beta.1:
+
+### Changed
+- Widened dependency constraints so the library co-installs with a broader range of applications: `psr/log` now accepts `^1.0 || ^2.0 || ^3.0` (the library only consumes the interface, so every major works) and `rowbot/url` now accepts `^3.1.7 || ^4.0` (older majors avoid rowbot/url 4.x's hard requirements on `psr/log ^3` and newer `brick/math`, both common sources of version conflicts). Note: rowbot/url 3.x emits PHP 8.4 implicit-nullable deprecation notices internally; it is only loaded on PHP 8.4 (PHP 8.5+ uses the native `Uri\WhatWg\Url`), and Composer still picks 4.x unless another dependency forces an older version
+- CI now also runs the test suite against the lowest allowed dependency versions (`composer update --prefer-lowest`) to keep the widened constraints honest
+
 ## [v4.0.0-beta.1](https://github.com/fivefilters/readability.php/releases/tag/v4.0.0-beta.1)
 
 Ground-up port from the latest Readability.js (v0.6.0) using Claude's Fable model. Uses PHP 8.4's new DOM API and native parser. See [UPGRADE.md](UPGRADE.md) for the full 3.x → 4.0 migration guide.
diff --git a/composer.json b/composer.json
index 8e6cf33..0de3169 100644
--- a/composer.json
+++ b/composer.json
@@ -30,8 +30,8 @@
         "php": ">=8.4",
         "ext-dom": "*",
         "ext-mbstring": "*",
-        "psr/log": "^2.0 || ^3.0",
-        "rowbot/url": "^4.1"
+        "psr/log": "^1.0 || ^2.0 || ^3.0",
+        "rowbot/url": "^3.1.7 || ^4.0"
     },
     "suggest": {
         "ext-uri": "Native WHATWG URL parsing, used automatically on PHP 8.5+ instead of rowbot/url"
diff --git a/test/PhpFeaturesTest.php b/test/PhpFeaturesTest.php
index 8287682..0dcdf8e 100644
--- a/test/PhpFeaturesTest.php
+++ b/test/PhpFeaturesTest.php
@@ -107,7 +107,8 @@ public function testPsrLoggerReceivesMessages(): void
             /** @var list<string> */
             public array $messages = [];
 
-            public function log($level, string|\Stringable $message, array $context = []): void
+            // Untyped $level/$message keep this compatible with every psr/log major (v1 has no parameter types).
+            public function log($level, $message, array $context = []): void
             {
                 $this->messages[] = (string) $message;
             }