diff --git a/src/Env.php b/src/Env.php
index 27ee6b4..89a2621 100644
--- a/src/Env.php
+++ b/src/Env.php
@@ -23,7 +23,7 @@ class Env extends Hash
 
     public function get(string $key)
     {
-        if ($this->has($key)) {
+        if (array_key_exists($key, $this->data)) {
             return $this->data[$key];
         } elseif ($this->parent) {
             return $this->parent->get($key);
diff --git a/src/Hash.php b/src/Hash.php
index ce09a70..1ce8ee8 100644
--- a/src/Hash.php
+++ b/src/Hash.php
@@ -5,7 +5,7 @@ class Hash extends Collection
 {
     public function get(string $key)
     {
-        if ($this->has($key)) {
+        if (array_key_exists($key, $this->data)) {
             return $this->data[$key];
         }
 
diff --git a/src/MList.php b/src/MList.php
index fa6d5a1..cf3a4dc 100644
--- a/src/MList.php
+++ b/src/MList.php
@@ -5,7 +5,7 @@ class MList extends Seq
 {
     public function get(int $index)
     {
-        if ($this->has($index)) {
+        if (array_key_exists($index, $this->data)) {
             return $this->data[$index];
         }
 
diff --git a/src/Vector.php b/src/Vector.php
index 20d229e..e3b0cd3 100644
--- a/src/Vector.php
+++ b/src/Vector.php
@@ -5,7 +5,7 @@ class Vector extends Seq
 {
     public function get(int $index)
     {
-        if ($this->has($index)) {
+        if (array_key_exists($index, $this->data)) {
             return $this->data[$index];
         }