diff --git a/src/Reflection/ReflectionDecoratedFunction.php b/src/Reflection/ReflectionDecoratedFunction.php
index cb8b628..0a61ba1 100644
--- a/src/Reflection/ReflectionDecoratedFunction.php
+++ b/src/Reflection/ReflectionDecoratedFunction.php
@@ -23,126 +23,176 @@ class ReflectionDecoratedFunction extends \ReflectionFunction
         $this->reflection = reflect($decorated);
     }
 
+    #[\ReturnTypeWillChange]
+
     public function inNamespace()
     {
         return $this->reflection->inNamespace();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isClosure()
     {
         return $this->reflection->isVariadic();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isDeprecated()
     {
         return $this->reflection->isDeprecated();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isInternal()
     {
         return $this->reflection->isInternal();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isUserDefined()
     {
         return $this->reflection->isUserDefined();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getClosureThis()
     {
         return $this->reflection->getClosureThis();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getClosureScopeClass()
     {
         return $this->reflection->getClosureScopeClass();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getDocComment()
     {
         return $this->reflection->getDocComment();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getEndLine()
     {
         return $this->reflection->getEndLine();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getExtension()
     {
         return $this->reflection->getExtension();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getExtensionName()
     {
         return $this->reflection->getExtensionName();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getFileName()
     {
         return $this->reflection->getFileName();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getName()
     {
         return $this->reflection->getName();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getNamespaceName()
     {
         return $this->reflection->getNamespaceName();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getNumberOfParameters()
     {
         return $this->reflection->getNumberOfParameters();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getNumberOfRequiredParameters()
     {
         return $this->reflection->getNumberOfRequiredParameters();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getParameters()
     {
         return $this->reflection->getParameters();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getReturnType()
     {
         return $this->reflection->getReturnType();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getShortName()
     {
         return $this->reflection->getShortName();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getStartLine()
     {
         return $this->reflection->getStartLine();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function getStaticVariables()
     {
         return $this->reflection->getStaticVariables();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function hasReturnType()
     {
         return $this->reflection->hasReturnType();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function returnsReference()
     {
         return $this->reflection->returnsReference();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isGenerator()
     {
         return $this->reflection->isGenerator();
     }
 
+    #[\ReturnTypeWillChange]
+
     public function isVariadic()
     {
         return $this->reflection->isVariadic();
diff --git a/src/Utils/CurriedFunction.php b/src/Utils/CurriedFunction.php
index faa32a4..0994467 100644
--- a/src/Utils/CurriedFunction.php
+++ b/src/Utils/CurriedFunction.php
@@ -25,7 +25,7 @@ class CurriedFunction extends PartiallyAppliedFunction
      * @param int|null $threshold
      * @param array    $args
      */
-    public function __construct(callable $callable, int $threshold = null, ...$args)
+    public function __construct(callable $callable, ?int $threshold = null, ...$args)
     {
         parent::__construct($callable, ...$args);
         $this->threshold = $threshold ?: reflect($callable)->getNumberOfRequiredParameters();
@@ -36,7 +36,7 @@ class CurriedFunction extends PartiallyAppliedFunction
         return $this->threshold;
     }
 
-    public function withThreshold(int $threshold = null)
+    public function withThreshold(?int $threshold = null)
     {
         return new static($this, $threshold);
     }
diff --git a/src/Utils/index.php b/src/Utils/index.php
index 72ca5be..fa9ce3f 100644
--- a/src/Utils/index.php
+++ b/src/Utils/index.php
@@ -47,7 +47,7 @@ function apply(callable $callable, ...$args)
     }
 }
 
-function curry(callable $callable, int $threshold = null, ...$args): CurriedFunction
+function curry(callable $callable, ?int $threshold = null, ...$args): CurriedFunction
 {
     return new CurriedFunction($callable, $threshold, ...$args);
 }