diff --git a/Dockerfile b/Dockerfile
index 34547f51f92..51d751ae541 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,14 +1,19 @@
 FROM ubuntu:focal
 
+ARG USER_ID
+ARG GROUP_ID
 ENV DEBIAN_FRONTEND noninteractive
 
-RUN apt-get update && apt-get install -y git cmake make ruby gcc python3 python3-pip
+RUN apt-get update && apt-get install -y git cmake make ruby gcc python3 python3-pip gcc-arm-none-eabi
 
 RUN pip install pyyaml
 
-RUN useradd inav
+# if either of these are already set the same as the user's machine, leave them be and ignore the error
+RUN addgroup --gid $GROUP_ID users; exit 0;
+RUN adduser --disabled-password --gecos '' --uid $USER_ID --gid $GROUP_ID user; exit 0;
 
-USER inav
+USER user
+RUN git config --global --add safe.directory /src
 
 VOLUME /src
 
diff --git a/build.sh b/build.sh
index 58db51aa421..fe5a5281e42 100755
--- a/build.sh
+++ b/build.sh
@@ -21,19 +21,29 @@ fi
 
 if [ -z "$(docker images -q inav-build)" ]; then
   echo -e "*** Building image\n"
-  docker build -t inav-build .
+  docker build -t inav-build --build-arg USER_ID="$(id -u)" --build-arg GROUP_ID="$(id -g)" .
   echo -ne "\n"
 fi
 
 if [ ! -d ./build ]; then
   echo -e "*** Creating build directory\n"
-  mkdir ./build
+  mkdir ./build && chmod 777 ./build
+fi
+
+if [ ! -d ./downloads ]; then
+  echo -e "*** Creating downloads directory\n"
+  mkdir ./downloads && chmod 777 ./downloads
+fi
+
+if [ ! -d ./tools ]; then
+  echo -e "*** Creating tools directory\n"
+  mkdir ./tools && chmod 777 ./tools
 fi
 
 echo -e "*** Building targets [$@]\n"
 docker run --rm -it -v "$(pwd)":/src inav-build $@
 
-if ls ./build/*.hex &> /dev/null; then
+if [ -z "$(ls ./build/*.hex &> /dev/null)" ]; then
   echo -e "\n*** Built targets in ./build:"
   stat -c "%n (%.19y)" ./build/*.hex
 fi