diff --git a/experiments/maki-interpreter/parser.js b/experiments/maki-interpreter/parser.js
index 758f444d..eda16bb3 100644
--- a/experiments/maki-interpreter/parser.js
+++ b/experiments/maki-interpreter/parser.js
@@ -292,6 +292,8 @@ function parseComand({ makiFile, length, pos, localFunctions }) {
       arg = argValue;
       break;
     }
+    default:
+      throw new Error("Invalid argType");
   }
 
   command.arguments = [arg];