diff --git a/rstan/rstan/R/zzz.R b/rstan/rstan/R/zzz.R
index de088444f..3f648c594 100644
--- a/rstan/rstan/R/zzz.R
+++ b/rstan/rstan/R/zzz.R
@@ -24,7 +24,7 @@ OUT <- 0
     assign("stanc_ctx", V8::v8(), envir = topenv())
   } else assign("stanc_ctx", QuickJSR::JSContext$new(stack_size = 4 * 1024 * 1024), envir = topenv())
   stanc_js <- system.file("stanc.js", package = "StanHeaders", mustWork = TRUE)
-  if (!stanc_ctx$validate(stanc_js)) {
+  if (!file.exists(stanc_js)) {
     stanc_js <- system.file("exec", "stanc.js", package = "rstan", mustWork = TRUE)
   }
   stanc_ctx$source(stanc_js)