diff --git a/semantic/semantic.go b/semantic/semantic.go
index 4e42dd6..2da8b76 100644
--- a/semantic/semantic.go
+++ b/semantic/semantic.go
@@ -3,14 +3,13 @@ package semantic
 import (
 	"fmt"
 	"ninja/ast"
-	"ninja/token"
 )
 
 // Semantic here is where we are going doing some semantic analysis
 // using visitor pattern
 type Semantic struct {
 	scopeStack     Stack
-	globalVariable map[string]ast.Expression
+	globalVariable []string
 	errors         []string
 }
 
@@ -43,6 +42,7 @@ func (s *Semantic) exitScope() {
 // declare will keep track of declare variables
 func (s *Semantic) declare(name string) {
 	if s.scopeStack.IsEmpty() {
+		s.globalVariable = append(s.globalVariable, name)
 		return
 	}
 
@@ -57,10 +57,12 @@ func (s *Semantic) resolve(name string) {
 		return
 	}
 
-	*peek = Scope{name: true}
+	(*peek)[name] = true
 }
 
-func (s *Semantic) expectIdentifierDeclare(name string, tok token.Token) bool {
+func (s *Semantic) expectIdentifierDeclare(ident *ast.Identifier) bool {
+	name := ident.Value
+	tok := ident.Token
 	peek, ok := s.scopeStack.Peek()
 	if !ok {
 		s.NewError("There aren't any scope active %s", name)
@@ -101,7 +103,7 @@ func (s *Semantic) analysis(node ast.Node) ast.Node {
 			s.analysis(v)
 		}
 	case *ast.Identifier:
-		s.expectIdentifierDeclare(node.Value, node.Token)
+		s.expectIdentifierDeclare(node)
 	case *ast.VarStatement:
 		s.declare(node.Name.Value)
 		s.analysis(node.Value)
diff --git a/semantic/semantic_test.go b/semantic/semantic_test.go
index dbf0bd6..fdd5cb5 100644
--- a/semantic/semantic_test.go
+++ b/semantic/semantic_test.go
@@ -103,6 +103,15 @@ func TestScopeVariablesWrong(t *testing.T) {
 	}
 }
 
+func TestMarkVariableAsGlobal(t *testing.T) {
+	s := testSemantic("var a = 0", t)
+
+	if len(s.globalVariable) <= 0 {
+		t.Fatalf("Variable a isn't mark as global")
+	}
+
+}
+
 // checkParserErrors check if there are parser errors
 func checkParserErrors(t *testing.T, p *parser.Parser) {
 	errors := p.Errors()