diff --git a/composer.json b/composer.json
index e703b8bd..d2500b3b 100644
--- a/composer.json
+++ b/composer.json
@@ -39,7 +39,7 @@
     "require-dev": {
         "amphp/php-cs-fixer-config": "^2",
         "phpunit/phpunit": "^9",
-        "psalm/phar": "^5.18"
+        "psalm/phar": "5.23.1"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Future/UnhandledFutureError.php b/src/Future/UnhandledFutureError.php
index 8cfc927d..1c6e04c9 100644
--- a/src/Future/UnhandledFutureError.php
+++ b/src/Future/UnhandledFutureError.php
@@ -13,7 +13,7 @@ public function __construct(\Throwable $previous, ?string $origin = null)
             . '"; Await the Future with Future::await() before the future is destroyed or use '
             . 'Future::ignore() to suppress this exception.';
 
-        if ($origin) {
+        if ($origin !== null) {
             $message .= ' The future has been created at ' . $origin;
         } else {
             $message .= ' Enable assertions and set AMP_DEBUG=true in the process environment to track its origin.';
diff --git a/src/Internal/functions.php b/src/Internal/functions.php
index 00dca1b2..2ebed1a5 100644
--- a/src/Internal/functions.php
+++ b/src/Internal/functions.php
@@ -44,6 +44,7 @@ function formatStacktrace(array $trace): string
  */
 function isDebugEnabled(): bool
 {
+    /** @psalm-suppress RiskyTruthyFalsyComparison */
     $env = \getenv("AMP_DEBUG") ?: "0";
     return match ($env) {
         "0", "false", "off" => false,