diff --git a/server/gameserver/lispenv.cc b/server/gameserver/lispenv.cc
index b23f648a..d42bc517 100644
--- a/server/gameserver/lispenv.cc
+++ b/server/gameserver/lispenv.cc
@@ -36,6 +36,12 @@ public:
     std::shared_ptr<a8::lisp::Value> Compile(const std::string& script)
     {
         auto expr = a8::lisp::Expr::Compile(script, shared_from_this());
+        if (!expr) {
+            abort();
+        }
+        if (!expr->IsType(a8::lisp::ValueType::kList)) {
+            abort();
+        }
         return expr;
     }