diff --git a/src/protocol/ast_printer.rs b/src/protocol/ast_printer.rs
index a788c9be9fb03ca95f022fc9e4c0b424814e366a..1f1a37a352675b6071b3d04b9a3e494270d0c9ec 100644
--- a/src/protocol/ast_printer.rs
+++ b/src/protocol/ast_printer.rs
@@ -704,6 +704,9 @@ impl ASTWriter {
                 self.kv(indent2).with_s_key("Parent")
                     .with_custom_val(|v| write_expression_parent(v, &expr.parent));
             },
+            Expression::Cast(expr) => {
+                todo!("print casting expression")
+            }
             Expression::Call(expr) => {
                 self.kv(indent).with_id(PREFIX_CALL_EXPR_ID, expr.this.0.index)
                     .with_s_key("CallExpr");