diff --git a/smnp/main.py b/smnp/main.py
index e68357a..d0b5b55 100644
--- a/smnp/main.py
+++ b/smnp/main.py
@@ -8,7 +8,7 @@ from smnp.program.interpreter import Interpreter
 def main():
     try:
         stdLibraryEnv = loadStandardLibrary()
-        Interpreter.interpretFile(sys.argv[1], printTokens=False, printAst=True, execute=True, baseEnvironment=stdLibraryEnv)
+        Interpreter.interpretFile(sys.argv[1], printTokens=False, printAst=False, execute=True, baseEnvironment=stdLibraryEnv)
         #draft()
         #tokens = tokenize(['function a(b...) { x+y}'])
         #FunctionDefinitionParser(tokens).node.print()
diff --git a/smnp/runtime/evaluator.py b/smnp/runtime/evaluator.py
index a3ca29e..d722577 100644
--- a/smnp/runtime/evaluator.py
+++ b/smnp/runtime/evaluator.py
@@ -1,5 +1,6 @@
 from smnp.ast.node.block import Block
 from smnp.ast.node.condition import IfElse
+from smnp.ast.node.extend import Extend
 from smnp.ast.node.function import FunctionDefinition
 from smnp.ast.node.imports import Import
 from smnp.ast.node.program import Program
@@ -75,6 +76,7 @@ def evaluate(node, environment):
     from smnp.runtime.evaluators.imports import ImportEvaluator
     from smnp.runtime.evaluators.function import FunctionDefinitionEvaluator
     from smnp.runtime.evaluators.function import ReturnEvaluator
+    from smnp.runtime.evaluators.extend import ExtendEvaluator
     result = Evaluator.oneOf(
         Evaluator.forNodes(ProgramEvaluator.evaluate, Program),
         Evaluator.forNodes(IfElseStatementEvaluator.evaluate, IfElse),
@@ -82,6 +84,7 @@ def evaluate(node, environment):
         Evaluator.forNodes(ImportEvaluator.evaluate, Import),
         Evaluator.forNodes(FunctionDefinitionEvaluator.evaluate, FunctionDefinition),
         Evaluator.forNodes(ReturnEvaluator.evaluate, Return),
+        Evaluator.forNodes(ExtendEvaluator.evaluate, Extend),
         #Evaluator.forNodes(ImportEvaluator.evaluate, ImportNode),
         #Evaluator.forNodes(FunctionDefinitionEvaluator.evaluate, FunctionDefinitionNode),
         #Evaluator.forNodes(ExtendEvaluator.evaluate, ExtendNode),
diff --git a/smnp/runtime/evaluators/extend.py b/smnp/runtime/evaluators/extend.py
index f1747f9..546487c 100644
--- a/smnp/runtime/evaluators/extend.py
+++ b/smnp/runtime/evaluators/extend.py
@@ -17,11 +17,11 @@ class ExtendEvaluator(Evaluator):
     @classmethod
     def _typeToMethodSignature(cls, node):
         if type(node.specifiers) == NoneNode:
-            return signature(ofType(node.type))
+            return signature(ofType(node.type.value))
 
-        elif node.type == Type.LIST:
+        elif node.type.value == Type.LIST:
             return signature(listSpecifier(node.specifiers[0]))
-        elif node.type == Type.MAP:
+        elif node.type.value == Type.MAP:
             return signature(mapSpecifier(node.specifiers[0], node.specifiers[1]))
 
     @classmethod