diff --git a/src/Illuminate/Contracts/Validation/InvokableRule.php b/src/Illuminate/Contracts/Validation/InvokableRule.php
index bed9ed567fb4..17c296446945 100644
--- a/src/Illuminate/Contracts/Validation/InvokableRule.php
+++ b/src/Illuminate/Contracts/Validation/InvokableRule.php
@@ -14,7 +14,7 @@ interface InvokableRule
      *
      * @param  string  $attribute
      * @param  mixed  $value
-     * @param  \Closure(string, ?string = null): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     * @param  \Closure(string, ?string=): \Illuminate\Translation\PotentiallyTranslatedString  $fail
      * @return void
      */
     public function __invoke(string $attribute, mixed $value, Closure $fail);
diff --git a/src/Illuminate/Contracts/Validation/ValidationRule.php b/src/Illuminate/Contracts/Validation/ValidationRule.php
index c687b26a2d98..6829372b3714 100644
--- a/src/Illuminate/Contracts/Validation/ValidationRule.php
+++ b/src/Illuminate/Contracts/Validation/ValidationRule.php
@@ -11,7 +11,7 @@ interface ValidationRule
      *
      * @param  string  $attribute
      * @param  mixed  $value
-     * @param  \Closure(string, ?string = null): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     * @param  \Closure(string, ?string=): \Illuminate\Translation\PotentiallyTranslatedString  $fail
      * @return void
      */
     public function validate(string $attribute, mixed $value, Closure $fail): void;
diff --git a/src/Illuminate/Foundation/Console/stubs/rule.implicit.stub b/src/Illuminate/Foundation/Console/stubs/rule.implicit.stub
index e04915bf5852..fa23cdfc2139 100644
--- a/src/Illuminate/Foundation/Console/stubs/rule.implicit.stub
+++ b/src/Illuminate/Foundation/Console/stubs/rule.implicit.stub
@@ -17,7 +17,7 @@ class {{ class }} implements ValidationRule
     /**
      * Run the validation rule.
      *
-     * @param  \Closure(string, ?string = null): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     * @param  \Closure(string, ?string=): \Illuminate\Translation\PotentiallyTranslatedString  $fail
      */
     public function validate(string $attribute, mixed $value, Closure $fail): void
     {
diff --git a/src/Illuminate/Foundation/Console/stubs/rule.stub b/src/Illuminate/Foundation/Console/stubs/rule.stub
index 7b54420895b4..bc1d35139247 100644
--- a/src/Illuminate/Foundation/Console/stubs/rule.stub
+++ b/src/Illuminate/Foundation/Console/stubs/rule.stub
@@ -10,7 +10,7 @@ class {{ class }} implements ValidationRule
     /**
      * Run the validation rule.
      *
-     * @param  \Closure(string, ?string = null): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     * @param  \Closure(string, ?string=): \Illuminate\Translation\PotentiallyTranslatedString  $fail
      */
     public function validate(string $attribute, mixed $value, Closure $fail): void
     {
diff --git a/types/Contracts/Validation/ValidationRule.php b/types/Contracts/Validation/ValidationRule.php
new file mode 100644
index 000000000000..565a7d972340
--- /dev/null
+++ b/types/Contracts/Validation/ValidationRule.php
@@ -0,0 +1,13 @@
+<?php
+
+use Illuminate\Contracts\Validation\ValidationRule;
+
+use function PHPStan\Testing\assertType;
+
+new class implements ValidationRule
+{
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        assertType('Closure(string, string|null=): Illuminate\Translation\PotentiallyTranslatedString', $fail);
+    }
+};