diff --git a/src/Evaluator/EvalArrayBinaryExpression.php b/src/Evaluator/EvalArrayBinaryExpression.php
index 96fd081..68bf03e 100644
--- a/src/Evaluator/EvalArrayBinaryExpression.php
+++ b/src/Evaluator/EvalArrayBinaryExpression.php
@@ -16,7 +16,7 @@ public function __invoke(
         ArrayObject $right,
     ): MonkeyObject {
         return match ($operator) {
-            '+' => new ArrayObject(array_merge($left->value, $right->value)),
+            '+' => new ArrayObject(array_merge($left->value(), $right->value())),
             default => ErrorObject::unknownOperator($left->typeLiteral(), $operator, $right->typeLiteral()),
         };
     }
diff --git a/src/Evaluator/EvalNumericBinaryExpression.php b/src/Evaluator/EvalNumericBinaryExpression.php
index 15f36d7..e04d366 100644
--- a/src/Evaluator/EvalNumericBinaryExpression.php
+++ b/src/Evaluator/EvalNumericBinaryExpression.php
@@ -16,18 +16,18 @@ public function __invoke(
         MonkeyObject $right,
     ): MonkeyObject {
         return match ($operator) {
-            '+' => new $left($left->value + $right->value),
-            '-' => new $left($left->value - $right->value),
-            '*' => new $left($left->value * $right->value),
-            '%' => new $left($left->value % $right->value),
-            '**' => new $left($left->value ** $right->value),
-            '/' => new $left($left->value / $right->value),
-            '<' => BooleanObject::from($left->value < $right->value),
-            '>' => BooleanObject::from($left->value > $right->value),
-            '<=' => BooleanObject::from($left->value <= $right->value),
-            '>=' => BooleanObject::from($left->value >= $right->value),
-            '!=' => BooleanObject::from($left->value !== $right->value),
-            '==' => BooleanObject::from($left->value === $right->value),
+            '+' => new $left($left->value() + $right->value()),
+            '-' => new $left($left->value() - $right->value()),
+            '*' => new $left($left->value() * $right->value()),
+            '%' => new $left($left->value() % $right->value()),
+            '**' => new $left($left->value() ** $right->value()),
+            '/' => new $left($left->value() / $right->value()),
+            '<' => BooleanObject::from($left->value() < $right->value()),
+            '>' => BooleanObject::from($left->value() > $right->value()),
+            '<=' => BooleanObject::from($left->value() <= $right->value()),
+            '>=' => BooleanObject::from($left->value() >= $right->value()),
+            '!=' => BooleanObject::from($left->value() !== $right->value()),
+            '==' => BooleanObject::from($left->value() === $right->value()),
             default => ErrorObject::unknownOperator($left->typeLiteral(), $operator, $right->typeLiteral()),
         };
     }
diff --git a/src/Evaluator/EvalStringBinaryExpression.php b/src/Evaluator/EvalStringBinaryExpression.php
index 86d5609..c8610c2 100644
--- a/src/Evaluator/EvalStringBinaryExpression.php
+++ b/src/Evaluator/EvalStringBinaryExpression.php
@@ -17,9 +17,9 @@ public function __invoke(
         StringObject $right,
     ): MonkeyObject {
         return match ($operator) {
-            '+' => new StringObject("{$left->value}{$right->value}"),
-            '!=' => BooleanObject::from($left->value !== $right->value),
-            '==' => BooleanObject::from($left->value === $right->value),
+            '+' => new StringObject("{$left->value()}{$right->value()}"),
+            '!=' => BooleanObject::from($left->value() !== $right->value()),
+            '==' => BooleanObject::from($left->value() === $right->value()),
             default => ErrorObject::unknownOperator($left->typeLiteral(), $operator, $right->typeLiteral()),
         };
     }