diff --git a/scripts/config.sh b/scripts/config.sh
index 54c5da6..43ac033 100644
--- a/scripts/config.sh
+++ b/scripts/config.sh
@@ -6,12 +6,8 @@ SCRIPTDIR="$( cd "$(dirname "$0")" ; pwd -P )"
 BUILDDIR="/build"
 # jdk repository directory
 JDKDIR="$BUILDDIR/jdk"
-# openjdk-build repo dir
-ABLDDIR="$BUILDDIR/openjdk-build"
-# openjdk-build repo
-ABLDREPO="https://github.com/AdoptOpenJDK/openjdk-build.git"
-# cacertfile
-CACERTFILE="$ABLDDIR/security/cacerts"
+# CA certificate database
+CACERTFILE="$BUILDDIR/cacerts"
 # hg tarball
 JAVA_TMP="$BUILDDIR/jdk_tmp"
 TARBALL_MAX_DOWNLOADS=10
diff --git a/scripts/fetch.sh b/scripts/fetch.sh
index 2ca54e0..37c7b6b 100644
--- a/scripts/fetch.sh
+++ b/scripts/fetch.sh
@@ -157,12 +157,3 @@ if [ ! -d "$JDKDIR" ]; then
 else
   echo "[FETCH] Directory for JDK repository exists, assuming everything has been done already." 2>&1
 fi
-
-
-if [ -d "$ABLDDIR" ]; then
-  rm -rf "$ABLDDIR"
-fi
-
-# clone the root project
-echo "[FETCH] Cloning openjdk-build repo"
-git clone --depth 1 "$ABLDREPO" "$ABLDDIR"
diff --git a/scripts/prepare.sh b/scripts/prepare.sh
index 6ed654e..f9699d3 100644
--- a/scripts/prepare.sh
+++ b/scripts/prepare.sh
@@ -33,3 +33,12 @@ if [ ! -d "$JTREG" ]; then
 else
   echo "[PREPARE] Using cached jtreg directory"
 fi
+
+if [ ! -f "$CACERTFILE" ]; then
+  echo "[PREPARE] Generating CA certificate database"
+  cd "$BUILDDIR"
+  wget -nv -N https://github.com/use-sparingly/keyutil/releases/download/0.4.0/keyutil-0.4.0.jar
+  wget -nv -N https://raw.githubusercontent.com/curl/curl/master/lib/mk-ca-bundle.pl
+  perl mk-ca-bundle.pl ca-bundle.crt
+  "$HOSTJDK/bin/java" -jar keyutil-0.4.0.jar --import --new-keystore "$CACERTFILE" --password changeit --force-new-overwrite --import-pem-file ca-bundle.crt
+fi