diff --git a/Application.php b/Application.php
index 769c65d63..9f9f8394e 100644
--- a/Application.php
+++ b/Application.php
@@ -1040,7 +1040,7 @@ protected function getDefaultInputDefinition()
             new InputOption('--quiet', '-q', InputOption::VALUE_NONE, 'Do not output any message'),
             new InputOption('--verbose', '-v|vv|vvv', InputOption::VALUE_NONE, 'Increase the verbosity of messages: 1 for normal output, 2 for more verbose output and 3 for debug'),
             new InputOption('--version', '-V', InputOption::VALUE_NONE, 'Display this application version'),
-            new InputOption('--ansi', '', InputOption::VALUE_NEGATABLE, 'Force (or disable --no-ansi) ANSI output', false),
+            new InputOption('--ansi', '', InputOption::VALUE_NEGATABLE, 'Force (or disable --no-ansi) ANSI output', null),
             new InputOption('--no-interaction', '-n', InputOption::VALUE_NONE, 'Do not ask any interactive question'),
         ]);
     }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 880856386..c41b65f14 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ CHANGELOG
  * Add support for bright colors
  * Add `#[AsCommand]` attribute for declaring commands on PHP 8
  * Add `Helper::width()` and `Helper::length()`
+ * The `--ansi` and `--no-ansi` options now default to `null`.
 
 5.2.0
 -----
diff --git a/Input/ArgvInput.php b/Input/ArgvInput.php
index a33ca3519..4568e45fe 100644
--- a/Input/ArgvInput.php
+++ b/Input/ArgvInput.php
@@ -134,7 +134,7 @@ private function parseLongOption(string $token)
         $name = substr($token, 2);
 
         if (false !== $pos = strpos($name, '=')) {
-            if (0 === \strlen($value = substr($name, $pos + 1))) {
+            if ('' === $value = substr($name, $pos + 1)) {
                 array_unshift($this->parsed, $value);
             }
             $this->addLongOption(substr($name, 0, $pos), $value);
diff --git a/Logger/ConsoleLogger.php b/Logger/ConsoleLogger.php
index c9ee03561..9abe713ff 100644
--- a/Logger/ConsoleLogger.php
+++ b/Logger/ConsoleLogger.php
@@ -17,6 +17,10 @@
 use Symfony\Component\Console\Output\ConsoleOutputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
+if ((new \ReflectionMethod(AbstractLogger::class, 'log'))->hasReturnType()) {
+    throw new \RuntimeException(sprintf('The "%s" logger is not compatible with psr/log >= 3.0. Try running "composer require psr/log:^2.".', ConsoleLogger::class));
+}
+
 /**
  * PSR-3 compliant console logger.
  *
diff --git a/Output/TrimmedBufferOutput.php b/Output/TrimmedBufferOutput.php
index 5455c5b47..3f4d375f4 100644
--- a/Output/TrimmedBufferOutput.php
+++ b/Output/TrimmedBufferOutput.php
@@ -24,7 +24,8 @@ class TrimmedBufferOutput extends Output
     private $maxLength;
     private $buffer = '';
 
-    public function __construct(int $maxLength, ?int $verbosity = self::VERBOSITY_NORMAL, bool $decorated = false, OutputFormatterInterface $formatter = null) {
+    public function __construct(int $maxLength, ?int $verbosity = self::VERBOSITY_NORMAL, bool $decorated = false, OutputFormatterInterface $formatter = null)
+    {
         if ($maxLength <= 0) {
             throw new InvalidArgumentException(sprintf('"%s()" expects a strictly positive maxLength. Got %d.', __METHOD__, $maxLength));
         }
diff --git a/Tests/Fixtures/application_1.md b/Tests/Fixtures/application_1.md
index fb1d089f4..1ecb4e62f 100644
--- a/Tests/Fixtures/application_1.md
+++ b/Tests/Fixtures/application_1.md
@@ -103,7 +103,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -230,7 +230,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
diff --git a/Tests/Fixtures/application_2.md b/Tests/Fixtures/application_2.md
index 75ed6bd5f..96d5431e6 100644
--- a/Tests/Fixtures/application_2.md
+++ b/Tests/Fixtures/application_2.md
@@ -116,7 +116,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -243,7 +243,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -318,7 +318,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -409,7 +409,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -481,7 +481,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
diff --git a/Tests/Fixtures/application_mbstring.md b/Tests/Fixtures/application_mbstring.md
index 148122295..e3838905f 100644
--- a/Tests/Fixtures/application_mbstring.md
+++ b/Tests/Fixtures/application_mbstring.md
@@ -107,7 +107,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -234,7 +234,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
@@ -325,7 +325,7 @@ Force (or disable --no-ansi) ANSI output
 * Is value required: no
 * Is multiple: no
 * Is negatable: yes
-* Default: `false`
+* Default: `NULL`
 
 #### `--no-interaction|-n`
 
diff --git a/composer.json b/composer.json
index 7598179c3..1984e520d 100644
--- a/composer.json
+++ b/composer.json
@@ -43,7 +43,6 @@
         "psr/log": "For using the console logger"
     },
     "conflict": {
-        "psr/log": ">=3",
         "symfony/dependency-injection": "<4.4",
         "symfony/dotenv": "<5.1",
         "symfony/event-dispatcher": "<4.4",