diff --git a/.bazelrc b/.bazelrc
index 65af315c82..ed8ea3a1b5 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -96,3 +96,6 @@ build --strategy=TypeScriptCompile=worker --strategy=AngularTemplateCompile=work
 # https://github.com/bazelbuild/bazel/issues/6341 for ongoing discussion with
 # upstream about this.
 build --javabase=@openjdk_linux_archive//:jdk --host_javabase=@openjdk_linux_archive//:jdk
+
+# Prevent falling back to the host JDK.
+startup --noautodetect_server_javabase
diff --git a/doc/make_bazel_package.sh b/doc/make_bazel_package.sh
index 1cd86267bd..0743bb272b 100755
--- a/doc/make_bazel_package.sh
+++ b/doc/make_bazel_package.sh
@@ -9,7 +9,7 @@ set -u
 
 BAZEL_SOURCE="$1"
 
-VERSION="4.0.0rc2-$(date +%Y%m%d%H%M)+$(GIT_DIR="${BAZEL_SOURCE}/.git" git rev-parse --short HEAD)"
+VERSION="4.0.0rc6-$(date +%Y%m%d%H%M)+$(GIT_DIR="${BAZEL_SOURCE}/.git" git rev-parse --short HEAD)"
 OUTPUT="bazel_${VERSION}"
 
 (
diff --git a/tools/bazel b/tools/bazel
index 21bb6193e7..a941938fe1 100755
--- a/tools/bazel
+++ b/tools/bazel
@@ -24,7 +24,7 @@ if [[ -n "${BAZEL_OVERRIDE+x}" ]]; then
   exec "${BAZEL_OVERRIDE}" "$@"
 fi
 
-readonly VERSION="4.0.0rc2-202012022031+a3c94ec2ed"
+readonly VERSION="4.0.0rc6-202012121845+159e00701d"
 
 readonly DOWNLOAD_DIR="${HOME}/.cache/bazel"
 # Directory to unpack bazel into.  This must change whenever bazel changes.