diff --git a/swift-ci/main/rhel-ubi/9/Dockerfile b/swift-ci/main/rhel-ubi/9/Dockerfile
index 57d90c6a5..ff77f61d3 100644
--- a/swift-ci/main/rhel-ubi/9/Dockerfile
+++ b/swift-ci/main/rhel-ubi/9/Dockerfile
@@ -1,7 +1,9 @@
 FROM redhat/ubi9
 
-RUN groupadd -g 42 build-user && \
-    useradd -m -r -u 42 -g build-user build-user
+ARG BUILD_USER_ID=42
+
+RUN groupadd -g ${BUILD_USER_ID} build-user && \
+    useradd -m -r -u ${BUILD_USER_ID} -g build-user build-user
 
 RUN yum install -y  \
   git               \