diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9d6ff58..1a067d2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,7 +18,6 @@ jobs:
     strategy:
       matrix:
         stack:
-          - scalingo-20
           - scalingo-22
     container:
       image: "scalingo/${{ matrix.stack }}:latest"
diff --git a/Makefile b/Makefile
index e2c8543..eaafd31 100644
--- a/Makefile
+++ b/Makefile
@@ -1,15 +1,15 @@
-STACK := "scalingo-20"
+STACK := "scalingo-22"
 BASH_COMMAND := /bin/bash
 
 .DEFAULT := all
 
 all: test
-test: test20 test22
+test: test22
 
 test22: STACK := "scalingo-22"
 
-test20 test22: BASH_COMMAND := test/run
-test20 test22: IMAGE := "scalingo/$(STACK):latest"
-test20 test22:
+test22: BASH_COMMAND := test/run
+test22: IMAGE := "scalingo/$(STACK):latest"
+test22:
 	@echo "Running tests in Docker using $(IMAGE)"
 	@docker run --pull always --mount type=bind,src=$(PWD),dst=/buildpack --workdir /buildpack --rm --interactive --tty --env "GITLAB_TOKEN=$(GITLAB_TOKEN)" --env "GITHUB_TOKEN=$(GITHUB_TOKEN)" --env "STACK=$(STACK)" $(IMAGE) bash -c "$(BASH_COMMAND)"
diff --git a/bin/compile b/bin/compile
index 7d37301..11dbf79 100755
--- a/bin/compile
+++ b/bin/compile
@@ -7,8 +7,8 @@ if [[ -n "${BUILDPACK_DEBUG}" ]]; then
   set -x
 fi
 
-readonly build_dir="${1}"
-readonly cache_dir="${2}"
+build_dir="${1}"
+cache_dir="${2}"
 env_dir="${3}"
 
 readonly java_version="${JAVA_VERSION:-1.8}"
@@ -33,6 +33,7 @@ install_webapp_runner() {
 
   local build_d
   local cache_d
+  local buildpack_d
 
   local tmp_d
   local jre_version
@@ -43,8 +44,9 @@ install_webapp_runner() {
 
   build_d="${1}"
   cache_d="${2}"
-  jre_version="${3}"
-  runner_version="${4}"
+  buildpack_d="${3}"
+  jre_version="${4}"
+  runner_version="${5}"
 
   local buildpacks_repository_url="https://buildpacks-repository.s3.eu-central-1.amazonaws.com"
 
@@ -54,6 +56,7 @@ install_webapp_runner() {
   echo "-----> Installing Webapp Runner ${runner_version}..."
 
   # Install JVM common tools:
+
   cached_jvm_common="${cache_d}/jvm-common.tar.xz"
 
   if [ ! -f "${cached_jvm_common}" ]
@@ -69,13 +72,12 @@ install_webapp_runner() {
         --directory "${tmp_d}"
 
     # Source utilities and functions:
-    source "${tmp_d}/bin/util"
     source "${tmp_d}/bin/java"
 
     echo "java.runtime.version=${jre_version}" \
         > "${build_d}/system.properties"
 
-    install_java_with_overlay "${build_d}"
+    install_openjdk "${build_d}" "${buildpack_d}"
 
     rm -Rf "${tmp_d}"
   }
@@ -102,5 +104,5 @@ install_webapp_runner() {
 readonly -f install_webapp_runner
 
 
-install_webapp_runner "${build_dir}" "${cache_dir}" \
+install_webapp_runner "${build_dir}" "${cache_dir}" "${buildpack_dir}" \
     "${java_version}" "${webapp_runner_version}"