diff --git a/src/Evaluator/Evaluator.cpp b/src/Evaluator/Evaluator.cpp
index 3885b18..8b27cff 100644
--- a/src/Evaluator/Evaluator.cpp
+++ b/src/Evaluator/Evaluator.cpp
@@ -22,6 +22,9 @@ void Evaluator::EvaluateBlockStatement(BoundBlockStatement* statement) {
 }
 
 void Evaluator::EvaluateExpressionStatement(BoundExpressionStatement *statement) {
+    // Delete previously saved value.
+    delete this->_scriptData->_lastValue;
+    // Save new value
     this->_scriptData->_lastValue = this -> EvaluateExpression(statement->GetExpression());
 }
 
diff --git a/src/Evaluator/Evaluator.hpp b/src/Evaluator/Evaluator.hpp
index a14a556..ad9dce6 100644
--- a/src/Evaluator/Evaluator.hpp
+++ b/src/Evaluator/Evaluator.hpp
@@ -30,6 +30,7 @@ class Evaluator {
 public:
     Evaluator(Script* script){
         _scriptData = script;
+        _result = nullptr;
     }
     void Evaluate(BoundScriptStatement* statement);
 
diff --git a/src/Script.cpp b/src/Script.cpp
index 4d32d97..60aea26 100644
--- a/src/Script.cpp
+++ b/src/Script.cpp
@@ -15,6 +15,8 @@ Script Script::Create(string script) {
 Script::Script() {
     Diagnostics = new class Diagnostics();
     _evaluator = new Evaluator(this);
+    _lastValue = nullptr;
+    BoundScript = nullptr;
 }
 
 void Script::Evaluate() {