diff --git a/test/run-test b/test/run-test
index 486b465..5fb3e4d 100755
--- a/test/run-test
+++ b/test/run-test
@@ -45,7 +45,7 @@
 export RUN="${progdir}/etc/run-test-jar"
 export DEX_LOCATION=/data/run-test/${test_dir}
 export NEED_DEX="true"
-export USE_JACK="true"
+export USE_JACK="false"
 export USE_DESUGAR="true"
 export SMALI_ARGS=""
 
diff --git a/test/testrunner/env.py b/test/testrunner/env.py
index b996b04..d45d009 100644
--- a/test/testrunner/env.py
+++ b/test/testrunner/env.py
@@ -33,7 +33,8 @@
                         'TARGET_ARCH',
                         'HOST_PREFER_32_BIT',
                         'HOST_OUT_EXECUTABLES',
-                        'ANDROID_JAVA_TOOLCHAIN']
+                        'ANDROID_JAVA_TOOLCHAIN',
+                        'ANDROID_COMPILE_WITH_JACK']
 _DUMP_MANY_VARS = None  # To be set to a dictionary with above list being the keys,
                         # and the build variable being the value.
 def _dump_many_vars(var_name):
@@ -78,6 +79,15 @@
 def _get_build_var(var_name):
   return _dump_many_vars(var_name)
 
+def _get_build_var_boolean(var, default):
+  val = _get_build_var(var)
+  if val:
+    if val == "True" or val == "true":
+      return True
+    if val == "False" or val == "false":
+      return False
+  return default
+
 def get_env(key):
   return _env.get(key)
 
@@ -97,7 +107,7 @@
 ANDROID_BUILD_TOP = _get_android_build_top()
 
 # Compiling with jack? Possible values in (True, False, 'default')
-ANDROID_COMPILE_WITH_JACK = _getEnvBoolean('ANDROID_COMPILE_WITH_JACK', 'default')
+ANDROID_COMPILE_WITH_JACK = _get_build_var_boolean('ANDROID_COMPILE_WITH_JACK', 'default')
 
 # Directory used for temporary test files on the host.
 ART_HOST_TEST_DIR = tempfile.mkdtemp(prefix = 'test-art-')
diff --git a/tools/buildbot-build.sh b/tools/buildbot-build.sh
index 75694c3..4f99ac3 100755
--- a/tools/buildbot-build.sh
+++ b/tools/buildbot-build.sh
@@ -19,6 +19,8 @@
   exit 1
 fi
 
+source build/envsetup.sh >&/dev/null # for get_build_var
+
 # Logic for setting out_dir from build/make/core/envsetup.mk:
 if [[ -z $OUT_DIR ]]; then
   if [[ -z $OUT_DIR_COMMON_BASE ]]; then
@@ -30,10 +32,7 @@
   out_dir=${OUT_DIR}
 fi
 
-using_jack=true
-if [[ $ANDROID_COMPILE_WITH_JACK == false ]]; then
-  using_jack=false
-fi
+using_jack=$(get_build_var ANDROID_COMPILE_WITH_JACK)
 
 java_libraries_dir=${out_dir}/target/common/obj/JAVA_LIBRARIES
 common_targets="vogar core-tests apache-harmony-jdwp-tests-hostdex jsr166-tests mockito-target"
@@ -63,7 +62,7 @@
   fi
 done
 
-if $using_jack; then
+if [[ $using_jack == "true" ]]; then
   common_targets="$common_targets ${out_dir}/host/linux-x86/bin/jack"
 fi
 
diff --git a/tools/run-jdwp-tests.sh b/tools/run-jdwp-tests.sh
index 17c84b4..d2322bb 100755
--- a/tools/run-jdwp-tests.sh
+++ b/tools/run-jdwp-tests.sh
@@ -19,24 +19,19 @@
   exit 1
 fi
 
-if [ -z "$ANDROID_JAVA_TOOLCHAIN" ] ; then
-  source build/envsetup.sh
-  setpaths # include platform prebuilt java, javac, etc in $PATH.
-fi
+source build/envsetup.sh >&/dev/null # for get_build_var, setpaths
+setpaths # include platform prebuilt java, javac, etc in $PATH.
 
 if [ -z "$ANDROID_HOST_OUT" ] ; then
   ANDROID_HOST_OUT=${OUT_DIR-$ANDROID_BUILD_TOP/out}/host/linux-x86
 fi
 
-using_jack=true
-if [[ $ANDROID_COMPILE_WITH_JACK == false ]]; then
-  using_jack=false
-fi
+using_jack=$(get_build_var ANDROID_COMPILE_WITH_JACK)
 
 function jlib_suffix {
   local str=$1
   local suffix="jar"
-  if $using_jack; then
+  if [[ $using_jack == "true" ]]; then
     suffix="jack"
   fi
   echo "$str.$suffix"
@@ -166,7 +161,7 @@
   art_debugee="$art_debugee -verbose:jdwp"
 fi
 
-if $using_jack; then
+if [[ $using_jack == "true" ]]; then
   toolchain_args="--toolchain jack --language JN --jack-arg -g"
 else
   toolchain_args="--toolchain jdk --language CUR"
diff --git a/tools/run-libcore-tests.sh b/tools/run-libcore-tests.sh
index d549098..eecdd2f 100755
--- a/tools/run-libcore-tests.sh
+++ b/tools/run-libcore-tests.sh
@@ -19,10 +19,8 @@
   exit 1
 fi
 
-if [ -z "$ANDROID_JAVA_TOOLCHAIN" ] ; then
-  source build/envsetup.sh
-  setpaths # include platform prebuilt java, javac, etc in $PATH.
-fi
+source build/envsetup.sh >&/dev/null # for get_build_var, setpaths
+setpaths # include platform prebuilt java, javac, etc in $PATH.
 
 if [ -z "$ANDROID_PRODUCT_OUT" ] ; then
   JAVA_LIBRARIES=out/target/common/obj/JAVA_LIBRARIES
@@ -30,16 +28,13 @@
   JAVA_LIBRARIES=${ANDROID_PRODUCT_OUT}/../../common/obj/JAVA_LIBRARIES
 fi
 
-using_jack=true
-if [[ $ANDROID_COMPILE_WITH_JACK == false ]]; then
-  using_jack=false
-fi
+using_jack=$(get_build_var ANDROID_COMPILE_WITH_JACK)
 
 function classes_jar_path {
   local var="$1"
   local suffix="jar"
 
-  if $using_jack; then
+  if [[ $using_jack == "true" ]]; then
     suffix="jack"
   fi
 
@@ -151,7 +146,7 @@
 vogar_args="$vogar_args --timeout 480"
 
 # Switch between using jack or javac+desugar+dx
-if $using_jack; then
+if [[ $using_jack == "true" ]]; then
   vogar_args="$vogar_args --toolchain jack --language JO"
 else
   vogar_args="$vogar_args --toolchain jdk --language CUR"