diff --git a/ts2panda/src/compiler.ts b/ts2panda/src/compiler.ts
index 19dfc5b49c2a6314930fa64a36a6c89daddbacc6..b43cb46a595b645d916165a1f143e362a60b213e 100644
--- a/ts2panda/src/compiler.ts
+++ b/ts2panda/src/compiler.ts
@@ -304,9 +304,9 @@ export class Compiler {
         if (!unreachableFlag) { // exit GlobalScopefunction or Function Block return
             if (this.funcBuilder instanceof AsyncFunctionBuilder) {
                 this.funcBuilder.resolve(NodeKind.Invalid, getVregisterCache(pandaGen, CacheList.undefined));
-                pandaGen.return(DebugInfo.getLastNode());
+                pandaGen.return(NodeKind.Invalid);
             } else {
-                pandaGen.returnUndefined(DebugInfo.getLastNode());
+                pandaGen.returnUndefined(NodeKind.Invalid);
             }
         }
     }
diff --git a/ts2panda/src/compilerDriver.ts b/ts2panda/src/compilerDriver.ts
index b71d158a8c665444add555d0c3afe56b45b3d5c5..ad0b8a91f37cddf7bae84335ca9064c5610f8913 100644
--- a/ts2panda/src/compilerDriver.ts
+++ b/ts2panda/src/compilerDriver.ts
@@ -148,7 +148,7 @@ export class CompilerDriver {
     }
 
     compileForSyntaxCheck(node: ts.SourceFile): void {
-       let recorder = this.compilePrologue(node, false);
+       let recorder = this.compilePrologue(node, false, true);
        checkDuplicateDeclaration(recorder);
     }
 
@@ -165,7 +165,7 @@ export class CompilerDriver {
             });
         }
 
-        let recorder = this.compilePrologue(node, true);
+        let recorder = this.compilePrologue(node, true, false);
 
         // initiate ts2abc
         if (!CmdOptions.isAssemblyMode()) {
@@ -245,7 +245,7 @@ export class CompilerDriver {
 
     compileUnitTest(node: ts.SourceFile, literalBufferArray?: Array<LiteralBuffer>): void {
         CompilerDriver.isTsFile = CompilerDriver.isTypeScriptSourceFile(node);
-        let recorder = this.compilePrologue(node, true);
+        let recorder = this.compilePrologue(node, true, true);
 
         for (let i = 0; i < this.pendingCompilationUnits.length; i++) {
             let unit: PendingCompilationUnit = this.pendingCompilationUnits[i];
@@ -281,7 +281,7 @@ export class CompilerDriver {
         }
     }
 
-    private compilePrologue(node: ts.SourceFile, recordType: boolean) {
+    private compilePrologue(node: ts.SourceFile, recordType: boolean, syntaxCheckStatus: boolean) {
         let topLevelScope: GlobalScope | ModuleScope;
         if (CmdOptions.isModules()) {
             topLevelScope = new ModuleScope(node);
@@ -293,7 +293,7 @@ export class CompilerDriver {
         if (enableTypeRecord) {
             TypeRecorder.createInstance();
         }
-        let recorder = new Recorder(node, topLevelScope, this, enableTypeRecord, CompilerDriver.isTsFile);
+        let recorder = new Recorder(node, topLevelScope, this, enableTypeRecord, CompilerDriver.isTsFile, syntaxCheckStatus);
         recorder.record();
         if (topLevelScope instanceof ModuleScope) {
             topLevelScope.module().setModuleEnvironment(topLevelScope);
diff --git a/ts2panda/src/index.ts b/ts2panda/src/index.ts
index 0342f1b209652bcb479226de6035d6e1ab5dfd99..77edf37d7fddee810e32bff0abf7aeb8b50e2dc1 100644
--- a/ts2panda/src/index.ts
+++ b/ts2panda/src/index.ts
@@ -161,7 +161,7 @@ namespace Compiler {
             allowJs: true,
             noEmitOnError: true,
             noImplicitAny: true,
-            target: ts.ScriptTarget.ES2015,
+            target: ts.ScriptTarget.ES2017,
             module: ts.ModuleKind.ES2015,
             strictNullChecks: true,
             skipLibCheck: true,
diff --git a/ts2panda/src/recorder.ts b/ts2panda/src/recorder.ts
index 6ca5732434a3ec7f37e10e472567b329e8ea1349..69b0d7d545d022f4adf9ad6bf14dd7afffbd19ae 100644
--- a/ts2panda/src/recorder.ts
+++ b/ts2panda/src/recorder.ts
@@ -72,8 +72,9 @@ export class Recorder {
     // [delete it when type system adapts for ESM]
     private importStmts: Array<ModuleStmt> = [];
     private exportStmts: Array<ModuleStmt> = [];
+    private syntaxCheckStatus: boolean;
 
-    constructor(node: ts.Node, scope: Scope, compilerDriver: CompilerDriver, recordType: boolean, isTsFile: boolean) {
+    constructor(node: ts.Node, scope: Scope, compilerDriver: CompilerDriver, recordType: boolean, isTsFile: boolean, syntaxCheckStatus: boolean) {
         this.node = node;
         this.scope = scope;
         this.compilerDriver = compilerDriver;
@@ -81,6 +82,7 @@ export class Recorder {
         this.funcNameMap = new Map<string, number>();
         this.funcNameMap.set("main", 1);
         this.isTsFile = isTsFile;
+        this.syntaxCheckStatus = syntaxCheckStatus;
     }
 
     record() {
@@ -121,7 +123,7 @@ export class Recorder {
 
     private recordInfo(node: ts.Node, scope: Scope) {
         node.forEachChild(childNode => {
-            if (!this.recordType) {
+            if (this.syntaxCheckStatus) {
                 checkSyntaxError(childNode, scope);
             }
             switch (childNode.kind) {
diff --git a/ts2panda/tests/lexenv.test.ts b/ts2panda/tests/lexenv.test.ts
index c63e6435a39f64441262ad569fcba5a972513e4d..9bdff800f31a86bf20c364f37ed1d5236b53abeb 100644
--- a/ts2panda/tests/lexenv.test.ts
+++ b/ts2panda/tests/lexenv.test.ts
@@ -118,7 +118,7 @@ describe("lexenv-compile-testcase in lexenv.test.ts", function () {
         let sourceFile = creatAstFromSnippet(source);
         let compilerDriver = new CompilerDriver('UnitTest');
         let globalScope = new GlobalScope(sourceFile);
-        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false);
+        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false, true);
         recorder.record();
 
         expect(globalScope, "root is null!").to.not.equal(null);
@@ -146,7 +146,7 @@ describe("lexenv-compile-testcase in lexenv.test.ts", function () {
         let sourceFile = creatAstFromSnippet(source);
         let compilerDriver = new CompilerDriver('UnitTest');
         let globalScope = new GlobalScope(sourceFile);
-        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false);
+        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false, true);
         recorder.record();
 
         let children = globalScope.getChildVariableScope();
@@ -194,7 +194,7 @@ describe("lexenv-compile-testcase in lexenv.test.ts", function () {
         let compilerDriver = new CompilerDriver('UnitTest');
         let globalScope = new GlobalScope(sourceFile);
 
-        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false);
+        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false, true);
         recorder.record();
         let postOrderVariableScopes = compilerDriver.postOrderAnalysis(globalScope);
 
@@ -218,7 +218,7 @@ describe("lexenv-compile-testcase in lexenv.test.ts", function () {
         let compilerDriver = new CompilerDriver('UnitTest');
         let globalScope = new GlobalScope(sourceFile);
 
-        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false);
+        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false, true);
         recorder.record();
         let postOrderVariableScopes = compilerDriver.postOrderAnalysis(globalScope);
 
@@ -272,7 +272,7 @@ describe("lexenv-compile-testcase in lexenv.test.ts", function () {
         let compilerDriver = new CompilerDriver('UnitTest');
         let globalScope = new GlobalScope(sourceFile);
 
-        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false);
+        let recorder = new Recorder(sourceFile, globalScope, compilerDriver, false, false, true);
         recorder.record();
         let postOrderVariableScopes = compilerDriver.postOrderAnalysis(globalScope);