diff --git a/native/jni/HostUnitTests.mk b/native/jni/HostUnitTests.mk
index 828edce61..967099a53 100644
--- a/native/jni/HostUnitTests.mk
+++ b/native/jni/HostUnitTests.mk
@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# HACK: Temporarily disable host tool build on Mac until the build system is ready for C++11.
+LATINIME_HOST_OSNAME := $(shell uname -s)
+ifneq ($(LATINIME_HOST_OSNAME), Darwin) # TODO: Remove this
+
 LOCAL_PATH := $(call my-dir)
 
 ######################################
@@ -47,7 +51,10 @@ LOCAL_SRC_FILES := $(addprefix $(LATIN_IME_TEST_SRC_DIR)/, $(LATIN_IME_CORE_TEST
 LOCAL_STATIC_LIBRARIES += liblatinime_host_static_for_unittests libgtest_host libgtest_main_host
 include $(BUILD_HOST_NATIVE_TEST)
 
+endif # Darwin - TODO: Remove this
+
 #################### Clean up the tmp vars
+LATINIME_HOST_OSNAME :=
 LATIN_IME_SRC_DIR :=
 LATIN_IME_TEST_SRC_DIR :=
 include $(LOCAL_PATH)/CleanupNativeFileList.mk