diff --git a/src/PhpCollection/AbstractMap.php b/src/PhpCollection/AbstractMap.php
index 20cb26d..0494b77 100644
--- a/src/PhpCollection/AbstractMap.php
+++ b/src/PhpCollection/AbstractMap.php
@@ -294,7 +294,7 @@ public function count()
 
     public function getIterator()
     {
-        return new \ArrayIterator($this->elements);
+        return new \ArrayIterator($this->elements ?: []);
     }
 
     protected function createNew(array $elements)
diff --git a/src/PhpCollection/AbstractSequence.php b/src/PhpCollection/AbstractSequence.php
index 5ce2bde..cf0fae1 100644
--- a/src/PhpCollection/AbstractSequence.php
+++ b/src/PhpCollection/AbstractSequence.php
@@ -355,11 +355,11 @@ public function count()
 
     public function getIterator()
     {
-        return new \ArrayIterator($this->elements);
+        return new \ArrayIterator($this->elements ?: []);
     }
 
     protected function createNew(array $elements)
     {
         return new static($elements);
     }
-}
\ No newline at end of file
+}
diff --git a/src/PhpCollection/Set.php b/src/PhpCollection/Set.php
index 1d70acc..3d2c063 100644
--- a/src/PhpCollection/Set.php
+++ b/src/PhpCollection/Set.php
@@ -52,7 +52,7 @@ public function last()
 
     public function getIterator()
     {
-        return new \ArrayIterator(array_values($this->elements));
+        return new \ArrayIterator(array_values($this->elements ?: []));
     }
 
     public function addSet(SetInterface $set)
@@ -446,4 +446,4 @@ private function insertElement($elem, $hash)
         $this->elements[$index] = $elem;
         $this->lookup[$hash][] = $index;
     }
-}
\ No newline at end of file
+}