diff --git a/build.sh b/build.sh
index a596668e..45e1d564 100755
--- a/build.sh
+++ b/build.sh
@@ -1,4 +1,8 @@
 #!/usr/bin/env bash
+declare -A cht_versions=(
+  ["cht-core-4-6"]="42807deaae818bf2085d0457f9f161073493aec1"
+)
+
 exit_on_error() {
   exit_code=$?
   if [[ $exit_code -ne 0 ]]; then
@@ -11,27 +15,29 @@ set -e
 trap exit_on_error EXIT
 
 if [ "$1" == "--force" ]; then
-  FORCE=true
+  FORCE=1
 fi
 
 npm ci --legacy-peer-deps
+rm -Rf build
+
+if [[ 1 == "$FORCE" ]]; then
+  rm -Rf dist
+else
+  for item in `ls dist | grep -v cht-core`; do
+      rm -rf dist/"$item"
+  done
+fi
 
-for item in `ls build | grep -v cht-core`; do
-    rm -rf $item
-done
-
-declare -a versions=("cht-core-4-6")
-for version in "${versions[@]}"; do
-  if [ -z ${FORCE+x} ] && [ -d dist/"$version" ]; then
+for version in "${!cht_versions[@]}"; do
+  if [[ ! 1 == "$FORCE" ]] && [ -d dist/"$version" ]; then
     printf "\033[0;32m== SKIPPING $version ==\n"
     continue
   fi
 
-  if [ -d build/"$version" ]; then
-    (cd build/"$version" && git fetch && git reset --hard origin/master)
-  else
-    git clone -b master https://github.com/medic/cht-core.git build/"$version"
-  fi
+  git clone https://github.com/medic/cht-core.git build/"$version"
+  (cd build/"$version" && git reset --hard "${cht_versions[$version]}")
+  (cd build/"$version" && git clean -df)
 
   (cd build/"$version" && npm ci)
 
@@ -47,9 +53,9 @@ for version in "${versions[@]}"; do
   mkdir -p dist/"$version"/enketo-transformer/xsl
   cp ./build/cht-core-4-6/api/src/xsl/openrosa2html5form.xsl dist/"$version"/xsl
   cp ./build/cht-core-4-6/api/src/enketo-transformer/xsl/* dist/"$version"/enketo-transformer/xsl
-done
 
-npx webpack --config cht-bundles/webpack.config.cht-core.js --env.cht='cht-core-4-6'
+  npx webpack --config cht-bundles/webpack.config.cht-core.js --env.cht="$version"
+done
 
 npx webpack