diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index a4751fd..0f38b80 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -104,7 +104,7 @@
 LOCAL_JACK_CLASSPATH:=
 LOCAL_JACK_COVERAGE_EXCLUDE_FILTER:=
 LOCAL_JACK_COVERAGE_INCLUDE_FILTER:=
-# '' (ie disabled), disabled, full, incremental
+# '' (ie disabled), disabled, full, incremental, javac_frontend
 LOCAL_JACK_ENABLED:=$(DEFAULT_JACK_ENABLED)
 LOCAL_JACK_FLAGS:=
 LOCAL_JACK_PLUGIN:=
diff --git a/core/config.mk b/core/config.mk
index 884be1e..2beaed4 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -610,11 +610,7 @@
 FAT16COPY := build/tools/fat16copy.py
 CHECK_LINK_TYPE := build/tools/check_link_type.py
 
-ifeq ($(ANDROID_COMPILE_WITH_JACK),true)
 DEFAULT_JACK_ENABLED:=full
-else
-DEFAULT_JACK_ENABLED:=
-endif
 ifneq ($(ANDROID_JACK_EXTRA_ARGS),)
 JACK_DEFAULT_ARGS :=
 DEFAULT_JACK_EXTRA_ARGS := $(ANDROID_JACK_EXTRA_ARGS)
diff --git a/core/configure_local_jack.mk b/core/configure_local_jack.mk
index 2270c88..f8049a3 100644
--- a/core/configure_local_jack.mk
+++ b/core/configure_local_jack.mk
@@ -18,18 +18,23 @@
 LOCAL_JACK_ENABLED := $(ANDROID_FORCE_JACK_ENABLED)
 endif
 
+ifneq ($(ANDROID_COMPILE_WITH_JACK),true)
+LOCAL_JACK_ENABLED :=
+endif
+
 LOCAL_JACK_ENABLED := $(strip $(LOCAL_JACK_ENABLED))
 LOCAL_MODULE := $(strip $(LOCAL_MODULE))
 
-ifneq ($(LOCAL_JACK_ENABLED),full)
-ifneq ($(LOCAL_JACK_ENABLED),incremental)
+valid_jack_enabled_values := full incremental javac_frontend disabled
+
 ifdef LOCAL_JACK_ENABLED
-ifneq ($(LOCAL_JACK_ENABLED),disabled)
-$(error $(LOCAL_PATH): invalid LOCAL_JACK_ENABLED "$(LOCAL_JACK_ENABLED)" for $(LOCAL_MODULE))
-endif
-endif
-LOCAL_JACK_ENABLED :=
-endif
+  ifneq ($(LOCAL_JACK_ENABLED),$(filter $(firstword $(LOCAL_JACK_ENABLED)),$(valid_jack_enabled_values)))
+    $(error $(LOCAL_PATH): invalid LOCAL_JACK_ENABLED "$(LOCAL_JACK_ENABLED)" for $(LOCAL_MODULE))
+  endif
+
+  ifeq ($(LOCAL_JACK_ENABLED),disabled)
+    LOCAL_JACK_ENABLED :=
+  endif
 endif
 
 ifdef $(LOCAL_MODULE).JACK_VERSION
diff --git a/core/definitions.mk b/core/definitions.mk
index e058bc1..3e99606 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2262,9 +2262,10 @@
 $(hide) mkdir -p $(PRIVATE_JACK_INTERMEDIATES_DIR)
 $(if $(PRIVATE_JACK_INCREMENTAL_DIR),$(hide) mkdir -p $(PRIVATE_JACK_INCREMENTAL_DIR))
 $(call dump-words-to-file,$(PRIVATE_JAVA_SOURCES),$(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list)
-$(hide) if [ -d "$(PRIVATE_SOURCE_INTERMEDIATES_DIR)" ]; then \
-          find $(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name '*.java' >> $(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list; \
-fi
+$(if $(PRIVATE_SOURCE_INTERMEDIATES_DIR), \
+    $(hide) if [ -d "$(PRIVATE_SOURCE_INTERMEDIATES_DIR)" ]; then \
+            find $(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name '*.java' >> $(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list; \
+    fi)
 $(if $(PRIVATE_HAS_PROTO_SOURCES), \
     $(hide) find $(PRIVATE_PROTO_SOURCE_INTERMEDIATES_DIR) -name '*.java' >> $(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list )
 $(if $(PRIVATE_HAS_RS_SOURCES), \
@@ -2281,6 +2282,10 @@
     $(hide) $(call add-java-resources-to,$@.res.tmp.zip)
     $(hide) unzip -qo $@.res.tmp.zip -d $@.res.tmp
     $(hide) rm $@.res.tmp.zip)
+$(if $(PRIVATE_JACK_IMPORT_JAR),
+    $(hide) mkdir -p $@.tmpjill.res
+    $(hide) unzip -qo $(PRIVATE_JACK_IMPORT_JAR) -d $@.tmpjill.res
+    $(hide) find $@.tmpjill.res -iname "*.class" -delete)
 $(hide) if [ -s $(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list-uniq ] ; then \
     export tmpEcjArg="@$(PRIVATE_JACK_INTERMEDIATES_DIR)/java-source-list-uniq"; \
 else \
@@ -2293,6 +2298,8 @@
         -D jack.dex.optimize="false") \
     $(if $(PRIVATE_RMTYPEDEFS), \
         -D jack.android.remove-typedef="true") \
+    $(if $(PRIVATE_JACK_IMPORT_JAR), \
+        --import $(PRIVATE_JACK_IMPORT_JAR) --import-resource $@.tmpjill.res) \
     $(addprefix --classpath ,$(strip \
         $(call normalize-path-list,$(PRIVATE_JACK_SHARED_LIBRARIES)))) \
     $(addprefix --import ,$(call reverse-list,$(PRIVATE_STATIC_JACK_LIBRARIES))) \
diff --git a/core/java.mk b/core/java.mk
index 78c8ba3..f6c66d5 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -340,7 +340,11 @@
 ifndef LOCAL_CHECKED_MODULE
 ifdef full_classes_jar
 ifdef LOCAL_JACK_ENABLED
+ifeq ($(LOCAL_JACK_ENABLED),javac_frontend)
+LOCAL_CHECKED_MODULE := $(full_classes_compiled_jar)
+else
 LOCAL_CHECKED_MODULE := $(jack_check_timestamp)
+endif
 else
 ifeq ($(LOCAL_IS_STATIC_JAVA_LIBRARY),true)
 LOCAL_CHECKED_MODULE := $(full_classes_compiled_jar)
@@ -774,6 +778,26 @@
 $(built_dex_intermediate): PRIVATE_JACK_COVERAGE_OPTIONS :=
 endif
 
+# Compiling with javac to jar, then converting jar to dex with jack
+ifeq ($(LOCAL_JACK_ENABLED),javac_frontend)
+
+# PRIVATE_EXTRA_JAR_ARGS and source files were already handled during javac
+$(built_dex_intermediate): PRIVATE_EXTRA_JAR_ARGS :=
+$(built_dex_intermediate): PRIVATE_JAVA_SOURCES :=
+$(built_dex_intermediate): PRIVATE_SOURCE_INTERMEDIATES_DIR :=
+$(built_dex_intermediate): PRIVATE_HAS_PROTO_SOURCES :=
+$(built_dex_intermediate): PRIVATE_HAS_RS_SOURCES :=
+
+# Incremental compilation is not supported when mixing javac and jack
+$(built_dex_intermediate): PRIVATE_JACK_INCREMENTAL_DIR :=
+
+# Pass output of javac to jack
+$(built_dex_intermediate): PRIVATE_JACK_IMPORT_JAR := $(full_classes_compiled_jar)
+$(built_dex_intermediate): $(full_classes_compiled_jar)
+else # LOCAL_JACK_ENABLED != javac_frontend
+$(built_dex_intermediate): PRIVATE_JACK_IMPORT_JAR :=
+endif # LOCAL_JACK_ENABLED != javac_frontend
+
 $(built_dex_intermediate): PRIVATE_JACK_PLUGIN_PATH := $(LOCAL_JACK_PLUGIN_PATH)
 $(built_dex_intermediate): PRIVATE_JACK_PLUGIN := $(LOCAL_JACK_PLUGIN)
 $(built_dex_intermediate): $(jack_all_deps) $(LOCAL_JACK_PLUGIN_PATH) | setup-jack-server