diff --git a/core/base_rules.mk b/core/base_rules.mk
index d0d0e11..6dcb7e7 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -43,6 +43,13 @@
 
 my_module_tags := $(LOCAL_MODULE_TAGS)
 
+LOCAL_JACK_ENABLED := $(strip $(LOCAL_JACK_ENABLED))
+ifneq ($(LOCAL_JACK_ENABLED),full)
+ifneq ($(LOCAL_JACK_ENABLED),incremental)
+LOCAL_JACK_ENABLED :=
+endif
+endif
+
 ###########################################################
 ## Validate and define fallbacks for input LOCAL_* variables.
 ###########################################################
@@ -682,7 +689,7 @@
 ###########################################################
 # JACK
 ###########################################################
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 ifdef need_compile_java
 
 full_static_jack_libs := \
@@ -757,7 +764,7 @@
 $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_ALL_JACK_LIBRARIES:= $(full_jack_libs)
 $(LOCAL_INTERMEDIATE_TARGETS) : PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
 
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 
 ###########################################################
 ## NOTICE files
diff --git a/core/cleanbuild.mk b/core/cleanbuild.mk
index 58b1ee4..159d66d 100644
--- a/core/cleanbuild.mk
+++ b/core/cleanbuild.mk
@@ -256,8 +256,13 @@
 
 .PHONY: clean-dex-files
 clean-dex-files:
-	$(hide) find $(OUT_DIR) -name "*.dex" | xargs rm -f
+	$(hide) find $(OUT_DIR) -name "*.dex" ! -path "*/jack-incremental/*" | xargs rm -f
 	$(hide) for i in `find $(OUT_DIR) -name "*.jar" -o -name "*.apk"` ; do ((unzip -l $$i 2> /dev/null | \
 				grep -q "\.dex$$" && rm -f $$i) || continue ) ; done
 	@echo "All dex files and archives containing dex files have been removed."
 
+.PHONY: clean-jack-incremental
+clean-jack-incremental:
+	$(hide) find $(OUT_DIR) -name "jack-incremental" -type d | xargs rm -rf
+	@echo "All jack incremental dirs have been removed."
+
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 085b5fc..d6441bb 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -107,7 +107,7 @@
 LOCAL_ADDITIONAL_JAVA_DIR:=
 LOCAL_ALLOW_UNDEFINED_SYMBOLS:=
 LOCAL_DX_FLAGS:=
-LOCAL_USE_JACK:= $(ANDROID_COMPILE_WITH_JACK)
+LOCAL_JACK_ENABLED:=$(DEFAULT_JACK_ENABLED) # '' (ie disabled), disabled, full, incremental
 LOCAL_JACK_VM_ARGS := $(DEFAULT_JACK_VM_ARGS)
 LOCAL_JACK_EXTRA_ARGS := $(DEFAULT_JACK_EXTRA_ARGS)
 LOCAL_JACK_FLAGS:=
diff --git a/core/config.mk b/core/config.mk
index 83ef074..a79eb62 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -406,6 +406,11 @@
 E2FSCK := $(HOST_OUT_EXECUTABLES)/e2fsck$(HOST_EXECUTABLE_SUFFIX)
 JARJAR := $(HOST_OUT_JAVA_LIBRARIES)/jarjar.jar
 
+ifeq ($(ANDROID_COMPILE_WITH_JACK),true)
+DEFAULT_JACK_ENABLED:=full
+else
+DEFAULT_JACK_ENABLED:=
+endif
 ifneq ($(strip $(ANDROID_JACK_VM)),)
 JACK_VM := $(ANDROID_JACK_VM)
 else
diff --git a/core/definitions.mk b/core/definitions.mk
index 6ff62ed..a0af072 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1731,6 +1731,7 @@
 $(hide) mkdir -p $(dir $@)
 $(hide) mkdir -p $(dir $(PRIVATE_CLASSES_JACK))
 $(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; \
@@ -1765,6 +1766,7 @@
     -D jack.import.type.policy=keep-first \
     --output-jack $(PRIVATE_CLASSES_JACK) \
     -D jack.java.source.version=1.7 \
+    $(if $(PRIVATE_JACK_INCREMENTAL_DIR),--incremental-folder $(PRIVATE_JACK_INCREMENTAL_DIR)) \
     --output-dex $(PRIVATE_JACK_INTERMEDIATES_DIR) \
     $(addprefix --config-jarjar ,$(strip $(PRIVATE_JARJAR_RULES))) \
     $(if $(PRIVATE_JACK_PROGUARD_FLAGS),--config-proguard $@.flags) \
@@ -1807,6 +1809,7 @@
 $(hide) rm -rf $(PRIVATE_JACK_INTERMEDIATES_DIR)
 $(hide) mkdir -p $(dir $@)
 $(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; \
@@ -1840,6 +1843,7 @@
     -D jack.import.resource.policy=keep-first \
     -D jack.import.type.policy=keep-first \
     -D jack.java.source.version=1.7 \
+    $(if $(PRIVATE_JACK_INCREMENTAL_DIR),--incremental-folder $(PRIVATE_JACK_INCREMENTAL_DIR)) \
     --output-jack $@ \
     $(addprefix --config-jarjar ,$(strip $(PRIVATE_JARJAR_RULES))) \
     $(if $(PRIVATE_JACK_PROGUARD_FLAGS),--config-proguard $@.flags) \
diff --git a/core/host_dalvik_java_library.mk b/core/host_dalvik_java_library.mk
index 9b92df6..f5da638 100644
--- a/core/host_dalvik_java_library.mk
+++ b/core/host_dalvik_java_library.mk
@@ -98,7 +98,7 @@
 	@echo Copying: $@
 	$(hide) $(ACP) -fp $< $@
 
-ifneq ($(LOCAL_USE_JACK),true)
+ifndef LOCAL_JACK_ENABLED
 $(built_dex): PRIVATE_INTERMEDIATES_DIR := $(intermediates.COMMON)
 $(built_dex): PRIVATE_DX_FLAGS := $(LOCAL_DX_FLAGS)
 $(built_dex): $(full_classes_jar) $(DX)
@@ -112,9 +112,17 @@
 	$(call initialize-package-file,$(PRIVATE_SOURCE_ARCHIVE),$@)
 	$(add-dex-to-package)
 
-else # LOCAL_USE_JACK
+else # LOCAL_JACK_ENABLED
 $(LOCAL_INTERMEDIATE_TARGETS): \
-	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jayces
+	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack-rsc
+
+ifeq ($(LOCAL_JACK_ENABLED),incremental)
+$(LOCAL_INTERMEDIATE_TARGETS): \
+	PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-incremental
+else
+$(LOCAL_INTERMEDIATE_TARGETS): \
+	PRIVATE_JACK_INCREMENTAL_DIR :=
+endif
 $(LOCAL_INTERMEDIATE_TARGETS):  PRIVATE_JACK_DEBUG_FLAGS := -g
 
 $(built_dex): PRIVATE_CLASSES_JACK := $(full_classes_jack)
@@ -134,7 +142,7 @@
 	$(add-dex-to-package)
 	$(add-carried-jack-resources)
 
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 
 USE_CORE_LIB_BOOTCLASSPATH :=
 
diff --git a/core/host_dalvik_static_java_library.mk b/core/host_dalvik_static_java_library.mk
index 6fe460e..bdce583 100644
--- a/core/host_dalvik_static_java_library.mk
+++ b/core/host_dalvik_static_java_library.mk
@@ -35,7 +35,14 @@
 $(full_classes_jack): PRIVATE_JACK_FLAGS := $(LOCAL_JACK_FLAGS)
 $(full_classes_jack): PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
 $(full_classes_jack): \
-	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack
+	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack-rsc
+ifeq ($(LOCAL_JACK_ENABLED),incremental)
+$(full_classes_jack): \
+	PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-incremental
+else
+$(full_classes_jack): \
+	PRIVATE_JACK_INCREMENTAL_DIR :=
+endif
 $(full_classes_jack): $(java_sources) $(java_resource_sources) $(full_jack_lib_deps) \
         $(jar_manifest_file) $(layers_file) $(LOCAL_MODULE_MAKEFILE) \
         $(LOCAL_ADDITIONAL_DEPENDENCIES) $(LOCAL_JARJAR_RULES) \
diff --git a/core/java.mk b/core/java.mk
index b80e8b8..d4f0039 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -471,7 +471,7 @@
     -verbose \
     $(legacy_proguard_flags)
 # not supported with jack
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
     $(error $(LOCAL_MODULE): Build with jack of instrumentation when obfuscating is not yet supported)
 endif
 
@@ -506,7 +506,7 @@
 
 endif # LOCAL_PROGUARD_ENABLED defined
 
-ifneq ($(strip $(LOCAL_USE_JACK)),true)
+ifndef LOCAL_JACK_ENABLED
 # Override PRIVATE_INTERMEDIATES_DIR so that install-dex-debug
 # will work even when intermediates != intermediates.COMMON.
 $(built_dex_intermediate): PRIVATE_INTERMEDIATES_DIR := $(intermediates.COMMON)
@@ -522,7 +522,7 @@
 endif
 $(built_dex_intermediate): $(full_classes_proguard_jar) $(DX)
 	$(transform-classes.jar-to-dex)
-endif # !LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED is disabled
 
 $(built_dex): $(built_dex_intermediate) | $(ACP)
 	@echo Copying: $@
@@ -562,9 +562,16 @@
 
 endif  # full_classes_jar is defined
 
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 $(LOCAL_INTERMEDIATE_TARGETS): \
-	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack
+	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack-rsc
+ifeq ($(LOCAL_JACK_ENABLED),incremental)
+$(LOCAL_INTERMEDIATE_TARGETS): \
+	PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-incremental
+else
+$(LOCAL_INTERMEDIATE_TARGETS): \
+	PRIVATE_JACK_INCREMENTAL_DIR :=
+endif
 
 ifdef full_classes_jar
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_JACK_DEBUG_FLAGS := -g
@@ -607,10 +614,15 @@
 # nothing to do it's built as a side effect of $(built_dex_intermediate)
 endif #LOCAL_IS_STATIC_JAVA_LIBRARY
 
-$(noshrob_classes_jack): PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/noshrob
+$(noshrob_classes_jack): PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack-noshrob-rsc
+ifeq ($(LOCAL_JACK_ENABLED),incremental)
+$(noshrob_classes_jack): PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-noshrob-incremental
+else
+$(noshrob_classes_jack): PRIVATE_JACK_INCREMENTAL_DIR :=
+endif
 $(noshrob_classes_jack): PRIVATE_JACK_PROGUARD_FLAGS :=
 $(noshrob_classes_jack): $(jack_all_deps)
 	@echo Building with Jack: $@
 	$(java-to-jack)
 endif  # full_classes_jar is defined
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
diff --git a/core/java_library.mk b/core/java_library.mk
index 8641aad..5ba8267 100644
--- a/core/java_library.mk
+++ b/core/java_library.mk
@@ -69,13 +69,13 @@
 $(common_javalib.jar): PRIVATE_DONT_DELETE_JAR_DIRS := $(LOCAL_DONT_DELETE_JAR_DIRS)
 $(common_javalib.jar) : $(built_dex) $(java_resource_sources)
 	@echo "target Jar: $(PRIVATE_MODULE) ($@)"
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 	$(create-empty-package)
 else
 	$(call initialize-package-file,$(PRIVATE_SOURCE_ARCHIVE),$@)
 endif
 	$(add-dex-to-package)
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 	$(add-carried-jack-resources)
 endif
 
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 06f0216..3c488f6 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -57,6 +57,13 @@
 endif
 LOCAL_MODULE_CLASS := APPS
 
+LOCAL_JACK_ENABLED := $(strip $(LOCAL_JACK_ENABLED))
+ifneq ($(LOCAL_JACK_ENABLED),full)
+ifneq ($(LOCAL_JACK_ENABLED),incremental)
+LOCAL_JACK_ENABLED :=
+endif
+endif
+
 # Package LOCAL_MODULE_TAGS default to optional
 LOCAL_MODULE_TAGS := $(strip $(LOCAL_MODULE_TAGS))
 ifeq ($(LOCAL_MODULE_TAGS),)
@@ -162,12 +169,12 @@
 endif # !custom
 LOCAL_PROGUARD_FLAGS := $(addprefix -include ,$(proguard_options_file)) $(LOCAL_PROGUARD_FLAGS)
 
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 ifndef LOCAL_JACK_PROGUARD_FLAGS
     LOCAL_JACK_PROGUARD_FLAGS := $(LOCAL_PROGUARD_FLAGS)
 endif
 LOCAL_JACK_PROGUARD_FLAGS := $(addprefix -include ,$(proguard_options_file)) $(LOCAL_JACK_PROGUARD_FLAGS)
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 
 ifeq (true,$(EMMA_INSTRUMENT))
 ifndef LOCAL_EMMA_INSTRUMENT
@@ -278,7 +285,7 @@
 # they want to use this module's R.java file.
 $(LOCAL_BUILT_MODULE): $(R_file_stamp)
 
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 ifneq ($(built_dex_intermediate),)
 $(built_dex_intermediate): $(R_file_stamp)
 endif
@@ -288,7 +295,7 @@
 ifneq ($(full_classes_jack),)
 $(full_classes_jack): $(R_file_stamp)
 endif
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 
 ifneq ($(full_classes_jar),)
 # If full_classes_jar is non-empty, we're building sources.
@@ -406,7 +413,7 @@
 $(LOCAL_BUILT_MODULE): PRIVATE_DONT_DELETE_JAR_DIRS := $(LOCAL_DONT_DELETE_JAR_DIRS)
 $(LOCAL_BUILT_MODULE): $(all_res_assets) $(jni_shared_libraries) $(full_android_manifest)
 	@echo "target Package: $(PRIVATE_MODULE) ($@)"
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 	$(create-empty-package)
 else
 	$(if $(PRIVATE_SOURCE_ARCHIVE),\
@@ -420,7 +427,7 @@
 ifneq ($(full_classes_jar),)
 	$(add-dex-to-package)
 endif
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 	$(add-carried-jack-resources)
 endif
 	$(sign-package)
diff --git a/core/static_java_library.mk b/core/static_java_library.mk
index c692f9f..c5d1b46 100644
--- a/core/static_java_library.mk
+++ b/core/static_java_library.mk
@@ -59,12 +59,12 @@
 
 LOCAL_PROGUARD_FLAGS := $(addprefix -include ,$(proguard_options_file)) $(LOCAL_PROGUARD_FLAGS)
 
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 ifndef LOCAL_JACK_PROGUARD_FLAGS
     LOCAL_JACK_PROGUARD_FLAGS := $(LOCAL_PROGUARD_FLAGS)
 endif
 LOCAL_JACK_PROGUARD_FLAGS := $(addprefix -include ,$(proguard_options_file)) $(LOCAL_JACK_PROGUARD_FLAGS)
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 
 endif  # LOCAL_RESOURCE_DIR
 
@@ -123,10 +123,10 @@
 	$(hide) find $(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name R.java | xargs cat > $@
 
 $(LOCAL_BUILT_MODULE): $(R_file_stamp)
-ifeq ($(LOCAL_USE_JACK),true)
+ifdef LOCAL_JACK_ENABLED
 $(noshrob_classes_jack): $(R_file_stamp)
 $(full_classes_jack): $(R_file_stamp)
-endif # LOCAL_USE_JACK
+endif # LOCAL_JACK_ENABLED
 $(full_classes_compiled_jar): $(R_file_stamp)
 
 # Rule to build AAR, archive including classes.jar, resource, etc.