diff --git a/src/Deferred.php b/src/Deferred.php
index 6bc40293..ef06069f 100644
--- a/src/Deferred.php
+++ b/src/Deferred.php
@@ -36,7 +36,7 @@ public function resolve($value = null)
         \call_user_func($this->resolveCallback, $value);
     }
 
-    public function reject($reason)
+    public function reject(\Throwable $reason)
     {
         $this->promise();
 
diff --git a/src/Promise.php b/src/Promise.php
index 0d75bde3..f25d3667 100644
--- a/src/Promise.php
+++ b/src/Promise.php
@@ -129,7 +129,7 @@ private function resolve($value = null)
         $this->settle(resolve($value));
     }
 
-    private function reject($reason)
+    private function reject(\Throwable $reason)
     {
         if (null !== $this->result) {
             return;
@@ -198,7 +198,7 @@ private function call(callable $callback)
                     function ($value = null) {
                         $this->resolve($value);
                     },
-                    function ($reason) {
+                    function (\Throwable $reason) {
                         $this->reject($reason);
                     }
                 );
diff --git a/src/RejectedPromise.php b/src/RejectedPromise.php
index bfa85655..d256b98f 100644
--- a/src/RejectedPromise.php
+++ b/src/RejectedPromise.php
@@ -62,7 +62,7 @@ public function otherwise(callable $onRejected)
 
     public function always(callable $onFulfilledOrRejected)
     {
-        return $this->then(null, function ($reason) use ($onFulfilledOrRejected) {
+        return $this->then(null, function (\Throwable $reason) use ($onFulfilledOrRejected) {
             return resolve($onFulfilledOrRejected())->then(function () use ($reason) {
                 return new RejectedPromise($reason);
             });
diff --git a/src/functions.php b/src/functions.php
index c70b44c4..4f2dc54f 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -188,7 +188,7 @@ function some(array $promisesOrValues, $howMany)
                 }
             };
 
-            $rejecter = function ($reason) use ($i, &$reasons, &$toReject, $toResolve, $reject) {
+            $rejecter = function (\Throwable $reason) use ($i, &$reasons, &$toReject, $toResolve, $reject) {
                 if ($toResolve < 1 || $toReject < 1) {
                     return;
                 }