diff --git a/ast/tests.go b/ast/tests.go
index 1da010d..5e58a4a 100644
--- a/ast/tests.go
+++ b/ast/tests.go
@@ -54,3 +54,21 @@ func NewAndTest() *AndTest {
 
 func (node *AndTest) orTestChild()              {}
 func (node *AndTest) Append(n AndTestChildNode) { node.ListNode.Append(n) }
+
+type NotTestChild interface {
+	Node
+	notTestChild()
+}
+
+type NotTest struct {
+	ParentNode
+}
+
+func NewNotTest() *NotTest {
+	node := &NotTest{}
+	node.initBaseNode(NOT_TEST)
+	return node
+}
+
+func (node *NotTest) notTestChild()           {}
+func (node *NotTest) SetChild(n NotTestChild) { node.ParentNode.SetChild(n) }
diff --git a/parser/parser.go b/parser/parser.go
index 599aff7..925977b 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -62,6 +62,12 @@ func (parser *Parser) parseCompoundStatement() *ast.CompoundStatement {
 	return compoundStmt
 }
 
+// not_test: 'not' not_test | comparison
+func (parser *Parser) parseNotTest() *ast.NotTest {
+	notTest := ast.NewNotTest()
+	return notTest
+}
+
 // and_test: not_test ('and' not_test)*
 func (parser *Parser) parseAndTest() *ast.AndTest {
 	andTest := ast.NewAndTest()