diff --git a/argon/lang/parser2/parser2.cpp b/argon/lang/parser2/parser2.cpp
index 200aee5d..bd327bb6 100644
--- a/argon/lang/parser2/parser2.cpp
+++ b/argon/lang/parser2/parser2.cpp
@@ -1213,6 +1213,8 @@ Node *Parser::ParseSyncBlock(Context *context) {
     this->Eat(true);
 
     expr = (ArObject *) this->ParseExpression(context, PeekPrecedence(TokenType::ASTERISK));
+    if (!expr)
+        throw ParserException(this->tkcur_.loc, kStandardError[0]);
 
     if (((Node *) expr.Get())->node_type == NodeType::LITERAL)
         throw ParserException(((Node *) expr.Get())->loc, kStandardError[14]);