diff --git a/core/build_id.mk b/core/build_id.mk
index 932e214..0e8e2cf 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -18,4 +18,4 @@
 # (like "CRB01").  It must be a single word, and is
 # capitalized by convention.
 
-export BUILD_ID=PI
+export BUILD_ID=MASTER
diff --git a/core/host_java_library.mk b/core/host_java_library.mk
index 47404c8..4b8ce11 100644
--- a/core/host_java_library.mk
+++ b/core/host_java_library.mk
@@ -97,16 +97,10 @@
 	$(MERGE_ZIPS) -j --ignore-duplicates $(if $(PRIVATE_JAR_MANIFEST),-m $(dir $@)/manifest.mf) \
             -stripDir META-INF -zipToNotStrip $< $@ $< $(call reverse-list,$(PRIVATE_STATIC_JAVA_LIBRARIES))
 
-#######################################
-LOCAL_JETIFIER_INPUT_FILE := $(full_classes_combined_jar)
-
-include $(BUILD_SYSTEM)/jetifier.mk
-#######################################
-
 # Run jarjar if necessary, otherwise just copy the file.
 ifneq ($(strip $(LOCAL_JARJAR_RULES)),)
 $(full_classes_jarjar_jar): PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
-$(full_classes_jarjar_jar): $(LOCAL_JETIFIER_OUTPUT_FILE) $(LOCAL_JARJAR_RULES) | $(JARJAR)
+$(full_classes_jarjar_jar): $(full_classes_combined_jar) $(LOCAL_JARJAR_RULES) | $(JARJAR)
 	@echo JarJar: $@
 	$(hide) $(JAVA) -jar $(JARJAR) process $(PRIVATE_JARJAR_RULES) $< $@
 else
diff --git a/core/java.mk b/core/java.mk
index ebb86af..20eb8c9 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -559,13 +559,7 @@
 full_classes_jarjar_jar := $(full_classes_processed_jar)
 endif
 
-#######################################
-LOCAL_JETIFIER_INPUT_FILE := $(full_classes_jarjar_jar)
-
-include $(BUILD_SYSTEM)/jetifier.mk
-#######################################
-
-$(eval $(call copy-one-file,$(LOCAL_JETIFIER_OUTPUT_FILE),$(full_classes_jar)))
+$(eval $(call copy-one-file,$(full_classes_jarjar_jar),$(full_classes_jar)))
 
 #######################################
 LOCAL_FULL_CLASSES_PRE_JACOCO_JAR := $(full_classes_jar)
diff --git a/core/jetifier.mk b/core/jetifier.mk
index 305c9dd..6ec8158 100644
--- a/core/jetifier.mk
+++ b/core/jetifier.mk
@@ -20,11 +20,11 @@
 ifeq ($(strip $(LOCAL_JETIFIER_ENABLED)),true)
   my_jetifier_input_path := $(LOCAL_JETIFIER_INPUT_FILE)
   my_files := $(intermediates.COMMON)/jetifier
-  my_jetifier_output_path := $(my_files)/classes-jetifier.jar
+  my_jetifier_output_path := $(my_files)/jetified-$(notdir $(my_jetifier_input_path))
 
 $(my_jetifier_output_path) : $(my_jetifier_input_path) $(JETIFIER)
 	rm -rf $@
-	$(JETIFIER) -outputfile $@ -i $<
+	$(JETIFIER) -l error -outputfile $@ -i $<
 
   LOCAL_JETIFIER_OUTPUT_FILE := $(my_jetifier_output_path)
   LOCAL_INTERMEDIATE_TARGETS += $(LOCAL_JETIFIER_OUTPUT_FILE)
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 96e2613..0efda57 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -571,6 +571,12 @@
 my_src_aar := $(filter %.aar, $(my_prebuilt_src_file))
 ifneq ($(my_src_aar),)
 # This is .aar file, archive of classes.jar and Android resources.
+
+# run Jetifier if needed
+LOCAL_JETIFIER_INPUT_FILE := $(my_src_aar)
+include $(BUILD_SYSTEM)/jetifier.mk
+my_src_aar := $(LOCAL_JETIFIER_OUTPUT_FILE)
+
 my_src_jar := $(intermediates.COMMON)/aar/classes.jar
 my_src_proguard_options := $(intermediates.COMMON)/aar/proguard.txt
 
@@ -582,6 +588,12 @@
 	$(hide) touch $@
 	# Make sure the proguard file exists and has a new timestamp.
 	$(hide) touch $(dir $@)/proguard.txt
+else
+
+# run Jetifier if needed
+LOCAL_JETIFIER_INPUT_FILE := $(my_src_jar)
+include $(BUILD_SYSTEM)/jetifier.mk
+my_src_jar := $(LOCAL_JETIFIER_OUTPUT_FILE)
 
 endif
 
diff --git a/core/sdk_check.mk b/core/sdk_check.mk
index 49ea2a8..c09fc7c 100644
--- a/core/sdk_check.mk
+++ b/core/sdk_check.mk
@@ -8,6 +8,11 @@
 
 whitelisted_modules := framework-res__auto_generated_rro
 
+
+ifeq (,$(JAVA_SDK_ENFORCEMENT_ERROR))
+  JAVA_SDK_ENFORCEMENT_ERROR := APPS
+endif
+
 ifeq ($(LOCAL_SDK_VERSION)$(LOCAL_PRIVATE_PLATFORM_APIS),)
   ifeq (,$(filter $(LOCAL_MODULE),$(whitelisted_modules)))
     ifneq ($(JAVA_SDK_ENFORCEMENT_WARNING)$(JAVA_SDK_ENFORCEMENT_ERROR),)