diff --git a/src/Standard.php b/src/Standard.php
index 63c7569..b1b9faa 100644
--- a/src/Standard.php
+++ b/src/Standard.php
@@ -214,6 +214,16 @@ public function unpack(?callable $func = null): self
         });
     }
 
+    /**
+     * Flattens inputs: arrays become lists.
+     *
+     * @return self
+     */
+    public function flatten(): self
+    {
+        return $this->unpack();
+    }
+
     /**
      * Chunks the pipeline into arrays with length elements. The last chunk may contain less than length elements.
      *
diff --git a/tests/UnpackTest.php b/tests/UnpackTest.php
index ac5c7a1..458354e 100644
--- a/tests/UnpackTest.php
+++ b/tests/UnpackTest.php
@@ -81,4 +81,16 @@ public function testWithIterator(): void
             [3],
         ])->unpack()->toArray());
     }
+
+    /**
+     * @covers \Pipeline\Standard::flatten()
+     */
+    public function testFlatten(): void
+    {
+        $this->assertSame([1, 2, 3], fromArray([
+            new ArrayIterator([1]),
+            fromArray([2]),
+            [3],
+        ])->flatten()->toArray());
+    }
 }