diff --git a/qlasskit/ast2ast/constantfolder.py b/qlasskit/ast2ast/constantfolder.py
index 4389aa18..6ab330bf 100644
--- a/qlasskit/ast2ast/constantfolder.py
+++ b/qlasskit/ast2ast/constantfolder.py
@@ -121,3 +121,15 @@ def visit_IfExp(self, node):
         if isinstance(node.test, ast.Constant):
             return node.body if node.test.value else node.orelse
         return node
+    
+    def visit_List(self, node):
+        elts = [self.visit(elt) for elt in node.elts]
+        if all(isinstance(elt, ast.Constant) for elt in elts):
+            return ast.Constant(value=[elt.value for elt in elts])
+        return ast.List(elts=elts, ctx=node.ctx)
+
+    def visit_Tuple(self, node):
+        elts = [self.visit(elt) for elt in node.elts]
+        if all(isinstance(elt, ast.Constant) for elt in elts):
+            return ast.Constant(value=tuple(elt.value for elt in elts))
+        return ast.Tuple(elts=elts, ctx=node.ctx)
\ No newline at end of file
diff --git a/test/test_ast2ast.py b/test/test_ast2ast.py
index 4dd778bd..6c17c7ec 100644
--- a/test/test_ast2ast.py
+++ b/test/test_ast2ast.py
@@ -63,7 +63,7 @@ def setUp(self):
         [
             ("a + (13 - 12 + 1)", "a + 2"),
             # ( "a + 13 - 12 + 1", "a + 2" ),
-            # ( "a + len([12])", "a + 1" ),
+            ( "a + len([12])", "a + 1" ),
             ("if True: a \nelse: b", "a"),
             ("a if False else b", "b"),
         ]