diff --git a/.github/workflows/lighty-rnc-app/simulator/Dockerfile b/.github/workflows/lighty-rnc-app/simulator/Dockerfile
index 0dad9bc25e..e8b6b7be6a 100644
--- a/.github/workflows/lighty-rnc-app/simulator/Dockerfile
+++ b/.github/workflows/lighty-rnc-app/simulator/Dockerfile
@@ -1,4 +1,4 @@
-ARG SIMULATOR_VERSION="21.3.0"
+ARG SIMULATOR_VERSION="21.4.0"
 
 FROM alpine:3.23.3 AS clone