diff --git a/build-with-srt-docker.sh b/build-with-srt-docker.sh
index b06a86ff..80898e11 100755
--- a/build-with-srt-docker.sh
+++ b/build-with-srt-docker.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# Usage example: $0 master soldier 0.20210618.0
 set -u
 
 if [ $# -eq 2 ]; then
@@ -11,9 +12,12 @@ BRANCH="${1:-master}"
 # soldier 0.20201022.1 or newer
 # scout 0.20201104.0 or newer
 RUNTIME="${2:-soldier}"
-VERSION="${3:-0.20201022.1}"
-IMAGE="steamrt_${RUNTIME}_amd64:mango-${VERSION}"
+VERSION="${3:-0.20210618.0}"
+IMAGE="steamrt_${RUNTIME}_${VERSION}_amd64:mango-${RUNTIME}"
 BASEURL="https://repo.steampowered.com/steamrt-images-${RUNTIME}/snapshots/${VERSION}"
+CACHEDIR="./cache/steamrt-images-${RUNTIME}/snapshots/${VERSION}"
+
+mkdir -p "${CACHEDIR}"
 
 echo -e "\e[1mBuilding branch \e[92m${BRANCH}\e[39m using \e[92m${RUNTIME}:${VERSION}\e[39m runtime\e[0m"
 
@@ -23,8 +27,8 @@ if ! docker inspect --type=image ${IMAGE} 2>&1 >/dev/null ; then
   mkdir -p ./cache/empty
   sed "s/%RUNTIME%/${RUNTIME}/g" steamrt.Dockerfile.in  > ./cache/steamrt.Dockerfile
 
-  wget -P ./cache -c ${BASEURL}/com.valvesoftware.SteamRuntime.Sdk-amd64,i386-${RUNTIME}-sysroot.tar.gz
-  cp --reflink=always "./cache/com.valvesoftware.SteamRuntime.Sdk-amd64,i386-${RUNTIME}-sysroot.tar.gz" ./cache/empty/
+  wget -P "${CACHEDIR}" -c ${BASEURL}/com.valvesoftware.SteamRuntime.Sdk-amd64,i386-${RUNTIME}-sysroot.tar.gz
+  cp --reflink=always "${CACHEDIR}/com.valvesoftware.SteamRuntime.Sdk-amd64,i386-${RUNTIME}-sysroot.tar.gz" ./cache/empty/
   docker build -f ./cache/steamrt.Dockerfile -t ${IMAGE} ./cache/empty
 fi