diff --git a/src/Illuminate/Collections/Arr.php b/src/Illuminate/Collections/Arr.php
index d4ebd89900a2..1ce093079f64 100644
--- a/src/Illuminate/Collections/Arr.php
+++ b/src/Illuminate/Collections/Arr.php
@@ -121,6 +121,23 @@ public static function dot($array, $prepend = '')
         return $results;
     }
 
+    /**
+     * Convert a flatten "dot" notation array into an expanded array.
+     *
+     * @param  iterable  $array
+     * @return array
+     */
+    public static function undot($array)
+    {
+        $results = [];
+
+        foreach ($array as $key => $value) {
+            static::set($results, $key, $value);
+        }
+
+        return $results;
+    }
+
     /**
      * Get all of the given array except for a specified array of keys.
      *
diff --git a/src/Illuminate/Collections/Collection.php b/src/Illuminate/Collections/Collection.php
index 6435b87ca64d..33b5b5de78f6 100644
--- a/src/Illuminate/Collections/Collection.php
+++ b/src/Illuminate/Collections/Collection.php
@@ -1435,6 +1435,16 @@ public function transform(callable $callback)
         return $this;
     }
 
+    /**
+     * Convert a flatten "dot" notation array into an expanded array.
+     *
+     * @return static
+     */
+    public function undot()
+    {
+        return new static(Arr::undot($this->all()));
+    }
+
     /**
      * Return only unique items from the collection array.
      *
diff --git a/src/Illuminate/Collections/LazyCollection.php b/src/Illuminate/Collections/LazyCollection.php
index 70f107061898..f0f2a8de20a2 100644
--- a/src/Illuminate/Collections/LazyCollection.php
+++ b/src/Illuminate/Collections/LazyCollection.php
@@ -1372,6 +1372,16 @@ public function tapEach(callable $callback)
         });
     }
 
+    /**
+     * Convert a flatten "dot" notation array into an expanded array.
+     *
+     * @return static
+     */
+    public function undot()
+    {
+        return $this->passthru('undot', []);
+    }
+
     /**
      * Return only unique items from the collection array.
      *
diff --git a/tests/Support/SupportArrTest.php b/tests/Support/SupportArrTest.php
index c38099cb2137..e34f469c848d 100644
--- a/tests/Support/SupportArrTest.php
+++ b/tests/Support/SupportArrTest.php
@@ -113,6 +113,30 @@ public function testDot()
         $this->assertEquals(['name' => 'taylor', 'languages.php' => true], $array);
     }
 
+    public function testUndot()
+    {
+        $array = Arr::undot([
+            'user.name' => 'Taylor',
+            'user.age' => 25,
+            'user.languages.0' => 'PHP',
+            'user.languages.1' => 'C#',
+        ]);
+        $this->assertEquals(['user' => ['name' => 'Taylor', 'age' => 25, 'languages' => ['PHP', 'C#']]], $array);
+
+        $array = Arr::undot([
+            'pagination.previous' => '<<',
+            'pagination.next' => '>>',
+        ]);
+        $this->assertEquals(['pagination' => ['previous' => '<<', 'next' => '>>']], $array);
+
+        $array = Arr::undot([
+            'foo',
+            'foo.bar' => 'baz',
+            'foo.baz' => ['a' => 'b'],
+        ]);
+        $this->assertEquals(['foo', 'foo' => ['bar' => 'baz', 'baz' => ['a' => 'b']]], $array);
+    }
+
     public function testExcept()
     {
         $array = ['name' => 'taylor', 'age' => 26];
diff --git a/tests/Support/SupportCollectionTest.php b/tests/Support/SupportCollectionTest.php
index 61727ce9ccc8..28f05639a4ab 100755
--- a/tests/Support/SupportCollectionTest.php
+++ b/tests/Support/SupportCollectionTest.php
@@ -4855,6 +4855,42 @@ public function testCollect($collection)
         ], $data->all());
     }
 
+    /**
+     * @dataProvider collectionClassProvider
+     */
+    public function testUndot($collection)
+    {
+        $data = $collection::make([
+            'name' => 'Taylor',
+            'meta.foo' => 'bar',
+            'meta.baz' => 'boom',
+            'meta.bam.boom' => 'bip',
+        ])->undot();
+        $this->assertSame([
+            'name' => 'Taylor',
+            'meta' => [
+                'foo' => 'bar',
+                'baz' => 'boom',
+                'bam' => [
+                    'boom' => 'bip',
+                ],
+            ],
+        ], $data->all());
+
+        $data = $collection::make([
+            'foo.0' => 'bar',
+            'foo.1' => 'baz',
+            'foo.baz' => 'boom',
+        ])->undot();
+        $this->assertSame([
+            'foo' => [
+                'bar',
+                'baz',
+                'baz' => 'boom',
+            ],
+        ], $data->all());
+    }
+
     /**
      * Provides each collection class, respectively.
      *