1 files changed, 4 insertions, 0 deletions
diff --git a/lib/internal/bootstrap/pre_execution.js b/lib/internal/bootstrap/pre_execution.js
index 820d931575..20b362f213 100644
--- a/lib/internal/bootstrap/pre_execution.js
+++ b/lib/internal/bootstrap/pre_execution.js
@@ -323,6 +323,10 @@ function initializeESMLoader() {
     const userLoader = getOptionValue('--loader');
     // If --loader is specified, create a loader with user hooks. Otherwise
     // create the default loader.
+    if (userLoader) {
+      const { emitExperimentalWarning } = require('internal/util');
+      emitExperimentalWarning('--loader');
+    }
     esm.initializeLoader(process.cwd(), userLoader);
   }
 }