diff --git a/php/bin/gherkin b/php/bin/gherkin
index a5cda8eba..f156ada32 100755
--- a/php/bin/gherkin
+++ b/php/bin/gherkin
@@ -7,11 +7,14 @@ use Cucumber\Gherkin\GherkinParser;
 use Cucumber\Messages\Source;
 use Cucumber\Messages\Streams\NdJson\NdJsonStreamWriter;
 
+assert(is_array($argv), "Script must be run from the command line");
+
 $options = ['predictable-ids', 'no-source', 'no-ast', 'no-pickles'];
 
 $selectedOptions = getopt('', $options, $restIndex);
 
 $paths = array_slice($argv, $restIndex);
+
 // lazily-read list of Sources
 $sources = (
     /** @param list<string> $paths */
diff --git a/php/bin/gherkin-generate-tokens b/php/bin/gherkin-generate-tokens
index 0c9ce2ed8..61a3a1897 100755
--- a/php/bin/gherkin-generate-tokens
+++ b/php/bin/gherkin-generate-tokens
@@ -9,6 +9,8 @@ namespace Cucumber\Gherkin;
 
 require __DIR__ . '/../vendor/autoload.php';
 
+assert(is_array($argv), "Script must be run from the command line");
+
 $parser = new Parser(new TokenFormatterBuilder());
 
 // first element is the script name
diff --git a/php/composer.json b/php/composer.json
index d3610acd9..1b6c871bf 100644
--- a/php/composer.json
+++ b/php/composer.json
@@ -19,7 +19,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^10.0",
-        "vimeo/psalm": "5.5.0",
+        "vimeo/psalm": "5.15.0",
         "friendsofphp/php-cs-fixer": "^3.5",
         "psalm/plugin-phpunit": "^0.18.0",
         "nikic/php-parser": "^4.14"