diff --git a/runner/actions-runner-dind-rootless.ubuntu-20.04.dockerfile b/runner/actions-runner-dind-rootless.ubuntu-20.04.dockerfile
index 7db70c11..1bd020ec 100644
--- a/runner/actions-runner-dind-rootless.ubuntu-20.04.dockerfile
+++ b/runner/actions-runner-dind-rootless.ubuntu-20.04.dockerfile
@@ -12,6 +12,10 @@ ARG DUMB_INIT_VERSION=1.2.5
 ARG DEBUG=false
 
 ENV DEBIAN_FRONTEND=noninteractive
+
+# Use 1001 for compatibility with GitHub-hosted runners
+ARG RUNNER_UID=1000
+
 RUN apt-get update -y \
     && apt-get install -y software-properties-common \
     && add-apt-repository -y ppa:git-core/ppa \
@@ -54,7 +58,7 @@ RUN apt-get update -y \
     && rm -rf /var/lib/apt/lists/*
 
 # Runner user
-RUN adduser --disabled-password --gecos "" --uid 1000 runner
+RUN adduser --disabled-password --gecos "" --uid $RUNNER_UID runner
 
 ENV HOME=/home/runner
 
@@ -98,9 +102,9 @@ RUN cd "$RUNNER_ASSETS_DIR" \
     && rm -f runner-container-hooks.zip
 
 # Make the rootless runner directory executable
-RUN mkdir /run/user/1000 \
-    && chown runner:runner /run/user/1000 \
-    && chmod a+x /run/user/1000
+RUN mkdir /run/user/$RUNNER_UID \
+    && chown runner:runner /run/user/$RUNNER_UID \
+    && chmod a+x /run/user/$RUNNER_UID
 
 # We place the scripts in `/usr/bin` so that users who extend this image can
 # override them with scripts of the same name placed in `/usr/local/bin`.
@@ -117,8 +121,8 @@ COPY hooks /etc/arc/hooks/
 # Add the Python "User Script Directory" to the PATH
 ENV PATH="${PATH}:${HOME}/.local/bin:/home/runner/bin"
 ENV ImageOS=ubuntu20
-ENV DOCKER_HOST=unix:///run/user/1000/docker.sock
-ENV XDG_RUNTIME_DIR=/run/user/1000
+ENV DOCKER_HOST=unix:///run/user/$RUNNER_UID/docker.sock
+ENV XDG_RUNTIME_DIR=/run/user/$RUNNER_UID
 
 RUN echo "PATH=${PATH}" > /etc/environment \
     && echo "ImageOS=${ImageOS}" >> /etc/environment \
diff --git a/runner/actions-runner-dind.ubuntu-20.04.dockerfile b/runner/actions-runner-dind.ubuntu-20.04.dockerfile
index 84608acb..07e04441 100644
--- a/runner/actions-runner-dind.ubuntu-20.04.dockerfile
+++ b/runner/actions-runner-dind.ubuntu-20.04.dockerfile
@@ -9,6 +9,10 @@ ARG DOCKER_VERSION=20.10.18
 ARG DOCKER_COMPOSE_VERSION=v2.6.0
 ARG DUMB_INIT_VERSION=1.2.5
 
+# Use 1001 and 121 for compatibility with GitHub-hosted runners
+ARG RUNNER_UID=1000
+ARG DOCKER_GID=1001
+
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -y \
     && apt-get install -y software-properties-common \
@@ -51,8 +55,8 @@ RUN apt-get update -y \
     && rm -rf /var/lib/apt/lists/*
 
 # Runner user
-RUN adduser --disabled-password --gecos "" --uid 1000 runner \
-    && groupadd docker \
+RUN adduser --disabled-password --gecos "" --uid $RUNNER_UID runner \
+    && groupadd docker --gid $DOCKER_GID \
     && usermod -aG sudo runner \
     && usermod -aG docker runner \
     && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers \
diff --git a/runner/actions-runner.ubuntu-20.04.dockerfile b/runner/actions-runner.ubuntu-20.04.dockerfile
index e5f755a2..ab45c29a 100644
--- a/runner/actions-runner.ubuntu-20.04.dockerfile
+++ b/runner/actions-runner.ubuntu-20.04.dockerfile
@@ -9,6 +9,10 @@ ARG DOCKER_VERSION=20.10.18
 ARG DOCKER_COMPOSE_VERSION=v2.6.0
 ARG DUMB_INIT_VERSION=1.2.5
 
+# Use 1001 and 121 for compatibility with GitHub-hosted runners
+ARG RUNNER_UID=1000
+ARG DOCKER_GID=1001
+
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -y \
     && apt-get install -y software-properties-common \
@@ -46,8 +50,8 @@ RUN apt-get update -y \
     && ln -sf /usr/bin/pip3 /usr/bin/pip \
     && rm -rf /var/lib/apt/lists/*
 
-RUN adduser --disabled-password --gecos "" --uid 1000 runner \
-    && groupadd docker \
+RUN adduser --disabled-password --gecos "" --uid $RUNNER_UID runner \
+    && groupadd docker --gid $DOCKER_GID \
     && usermod -aG sudo runner \
     && usermod -aG docker runner \
     && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers \