diff --git a/src/Result/Err.php b/src/Result/Err.php
index 257db0d..27e3bae 100644
--- a/src/Result/Err.php
+++ b/src/Result/Err.php
@@ -46,6 +46,10 @@ public function expect(string|Throwable $message): mixed
             throw $message;
         }
 
+        if ($this->err instanceof Throwable) {
+            throw new RuntimeException($message, previous: $this->err);
+        }
+
         throw new RuntimeException($message);
     }
 
diff --git a/src/Result/Ok.php b/src/Result/Ok.php
index 83f61bb..7462bf7 100644
--- a/src/Result/Ok.php
+++ b/src/Result/Ok.php
@@ -47,7 +47,11 @@ public function expect(string|Throwable $message): mixed
 
     public function expectErr(Throwable|string $message): mixed
     {
-        throw $message instanceof Throwable ? $message : new RuntimeException($message);
+        if ($message instanceof Throwable) {
+            throw $message;
+        }
+
+        throw new RuntimeException($message);
     }
 
     public function inspect(callable $f): Result