diff --git a/docker/Dockerfile b/docker/Dockerfile
index e0c6614072..c5c2a9e655 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:11 AS builder
+FROM eclipse-temurin:21 AS builder
 
 WORKDIR /opt/antlr4
 
@@ -14,23 +14,8 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install maven git -
     && mvn -DskipTests install --projects tool --also-make \
     && mv ./tool/target/antlr4-*-complete.jar antlr4-tool.jar
 
-FROM eclipse-temurin:11-jre
-
-ARG user=appuser
-ARG group=appuser
-ARG uid=1000
-ARG gid=1000
-
-RUN adduser \
-    --disabled-password \
-    --gecos "" \
-    --home "$(pwd)" \
-    --no-create-home \
-    --uid "${uid}" \
-    "${user}"
+FROM eclipse-temurin:21-jre
 
 COPY --from=builder /opt/antlr4/antlr4/antlr4-tool.jar /usr/local/lib/
 WORKDIR /work
 ENTRYPOINT ["java", "-Xmx500M", "-cp", "/usr/local/lib/antlr4-tool.jar", "org.antlr.v4.Tool"]
-
-