diff --git a/Dockerfile.legacy b/Dockerfile.legacy
index 83b1ce57..2f38ff93 100644
--- a/Dockerfile.legacy
+++ b/Dockerfile.legacy
@@ -1,6 +1,8 @@
 FROM composer:2.2 AS composer
 FROM php:5.6-fpm
 
+ARG UID
+
 #ENV PHP_MEMORY_LIMIT=1024M
 ENV DEBIAN_FRONTEND=noninteractive
 
@@ -21,7 +23,7 @@ RUN apt update && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /usr/share/doc/*
 
 # Create non-root user
-RUN useradd -ms /bin/bash phpuser
+RUN useradd -u ${UID} -ms /bin/bash phpuser
 WORKDIR /home/phpuser
 USER phpuser
 
diff --git a/Taskfile.yml b/Taskfile.yml
index 1648fffb..41ba698e 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -16,7 +16,7 @@ tasks:
   build:php5-6:
     desc: Build test container
     cmds:
-      - docker compose build php5-6
+      - docker compose build --build-arg UID="$(id -u)" php5-6
 
   test:
     desc: Run tests
diff --git a/compose.yml b/compose.yml
index e082bc04..aad59d7c 100644
--- a/compose.yml
+++ b/compose.yml
@@ -41,7 +41,6 @@ services:
     build:
       context: ./
       dockerfile: Dockerfile.legacy
-    user: ${UID:-1000}:${GID:-1000}
     volumes:
       - ./:/home/phpuser
       - /home/phpuser/src/vendor # do not mount vendor inside container