diff --git a/core/definitions.mk b/core/definitions.mk
index 5c76d77..7555e86 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2000,6 +2000,38 @@
 $(if $(PRIVATE_JAR_MANIFEST), $(hide) echo unsupported options JAR_MANIFEST in $@; exit 53)
 endef
 
+# Invoke Jack to compile java source just to check it compiles correctly.
+#
+# Some historical notes:
+# - below we write the list of java files to java-source-list to avoid argument
+#   list length problems with Cygwin
+# - we filter out duplicate java file names because Jack doesn't like them.
+define jack-check-java
+$(hide) rm -f $@
+$(hide) rm -f $@.java-source-list
+$(hide) rm -f $@.java-source-list-uniq
+$(hide) mkdir -p $(dir $@)
+$(if $(PRIVATE_JACK_INCREMENTAL_DIR),$(hide) mkdir -p $(PRIVATE_JACK_INCREMENTAL_DIR))
+$(call dump-words-to-file,$(PRIVATE_JAVA_SOURCES),$@.java-source-list)
+$(hide) if [ -d "$(PRIVATE_SOURCE_INTERMEDIATES_DIR)" ]; then \
+          find $(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name '*.java' >> $@.java-source-list; \
+fi
+$(hide) tr ' ' '\n' < $@.java-source-list \
+    | sort -u > $@.java-source-list-uniq
+$(hide) if [ -s $@.java-source-list-uniq ] ; then \
+	$(call call-jack,$(PRIVATE_JACK_EXTRA_ARGS)) \
+	    $(strip $(PRIVATE_JACK_FLAGS)) \
+	    $(strip $(PRIVATE_JACK_DEBUG_FLAGS)) \
+	    $(addprefix --classpath ,$(strip \
+	        $(call normalize-path-list,$(call reverse-list,$(PRIVATE_STATIC_JACK_LIBRARIES)) $(PRIVATE_BOOTCLASSPATH_JAVA_LIBRARIES) $(PRIVATE_ALL_JACK_LIBRARIES)))) \
+	    -D jack.import.resource.policy=keep-first \
+	    -D jack.import.type.policy=keep-first \
+	    $(if $(PRIVATE_JACK_INCREMENTAL_DIR),--incremental-folder $(PRIVATE_JACK_INCREMENTAL_DIR)) \
+	    @$@.java-source-list-uniq; \
+fi
+touch $@
+endef
+
 define transform-jar-to-jack
 	$(hide) mkdir -p $(dir $@)
 	$(hide) mkdir -p $@.tmpjill.res
diff --git a/core/host_dalvik_java_library.mk b/core/host_dalvik_java_library.mk
index 6678723..5b8634e 100644
--- a/core/host_dalvik_java_library.mk
+++ b/core/host_dalvik_java_library.mk
@@ -36,6 +36,7 @@
 full_classes_jarjar_jar := $(intermediates.COMMON)/classes-jarjar.jar
 full_classes_jar := $(intermediates.COMMON)/classes.jar
 full_classes_jack := $(intermediates.COMMON)/classes.jack
+jack_check_timestamp := $(intermediates.COMMON)/jack.check.timestamp
 built_dex := $(intermediates.COMMON)/classes.dex
 
 LOCAL_INTERMEDIATE_TARGETS += \
@@ -43,12 +44,17 @@
     $(full_classes_jarjar_jar) \
     $(full_classes_jack) \
     $(full_classes_jar) \
+    $(jack_check_timestamp) \
     $(built_dex)
 
 # See comment in java.mk
 ifndef LOCAL_CHECKED_MODULE
+ifdef LOCAL_JACK_ENABLED
+LOCAL_CHECKED_MODULE := $(jack_check_timestamp)
+else
 LOCAL_CHECKED_MODULE := $(full_classes_compiled_jar)
 endif
+endif
 
 #######################################
 include $(BUILD_SYSTEM)/base_rules.mk
@@ -120,16 +126,21 @@
 $(LOCAL_INTERMEDIATE_TARGETS): \
 	PRIVATE_JACK_INCREMENTAL_DIR :=
 endif
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_JACK_FLAGS := $(GLOBAL_JAVAC_DEBUG_FLAGS) $(LOCAL_JACK_FLAGS)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_JACK_VERSION := $(LOCAL_JACK_VERSION)
 
-$(built_dex): PRIVATE_CLASSES_JACK := $(full_classes_jack)
-$(built_dex): PRIVATE_JACK_FLAGS := $(GLOBAL_JAVAC_DEBUG_FLAGS) $(LOCAL_JACK_FLAGS)
-$(built_dex): PRIVATE_JACK_VERSION := $(LOCAL_JACK_VERSION)
-$(built_dex): $(java_sources) $(java_resource_sources) $(full_jack_deps) \
+jack_all_deps := $(java_sources) $(java_resource_sources) $(full_jack_deps) \
         $(jar_manifest_file) $(proto_java_sources_file_stamp) \
-        $(LOCAL_ADDITIONAL_DEPENDENCIES) $(JACK) | setup-jack-server
+        $(LOCAL_ADDITIONAL_DEPENDENCIES) $(JACK)
+$(built_dex): PRIVATE_CLASSES_JACK := $(full_classes_jack)
+$(built_dex): $(jack_all_deps) | setup-jack-server
 	@echo Building with Jack: $@
 	$(jack-java-to-dex)
 
+$(jack_check_timestamp): $(jack_all_deps) | setup-jack-server
+	@echo Checking build with Jack: $@
+	$(jack-check-java)
+
 # $(full_classes_jack) is just by-product of $(built_dex).
 # The dummy command was added because, without it, make misses the fact the $(built_dex) also
 # change $(full_classes_jack).
diff --git a/core/host_dalvik_static_java_library.mk b/core/host_dalvik_static_java_library.mk
index e1ffbfe..bdb13b7 100644
--- a/core/host_dalvik_static_java_library.mk
+++ b/core/host_dalvik_static_java_library.mk
@@ -35,8 +35,9 @@
 include $(BUILD_SYSTEM)/host_java_library.mk
 # proguard is not supported
 # *.proto files are not supported
-$(full_classes_jack): PRIVATE_JACK_FLAGS := $(GLOBAL_JAVAC_DEBUG_FLAGS) $(LOCAL_JACK_FLAGS)
-$(full_classes_jack): PRIVATE_JACK_VERSION := $(LOCAL_JACK_VERSION)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_JACK_FLAGS := $(GLOBAL_JAVAC_DEBUG_FLAGS) $(LOCAL_JACK_FLAGS)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_JACK_VERSION := $(LOCAL_JACK_VERSION)
+
 $(full_classes_jack): PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
 $(full_classes_jack): \
 	PRIVATE_JACK_INTERMEDIATES_DIR := $(intermediates.COMMON)/jack-rsc
diff --git a/core/java.mk b/core/java.mk
index 4485af6..77a2614 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -119,6 +119,7 @@
 full_classes_jack := $(intermediates.COMMON)/classes.jack
 # intermediate Jack library without shrink and obfuscation
 noshrob_classes_jack := $(intermediates.COMMON)/classes.noshrob.jack
+jack_check_timestamp := $(intermediates.COMMON)/jack.check.timestamp
 
 LOCAL_INTERMEDIATE_TARGETS += \
     $(full_classes_compiled_jar) \
@@ -129,6 +130,7 @@
     $(built_dex_intermediate) \
     $(full_classes_jack) \
     $(noshrob_classes_jack) \
+    $(jack_check_timestamp) \
     $(built_dex) \
     $(full_classes_stubs_jar)
 
@@ -323,9 +325,13 @@
 # command line.
 ifndef LOCAL_CHECKED_MODULE
 ifdef full_classes_jar
+ifdef LOCAL_JACK_ENABLED
+LOCAL_CHECKED_MODULE := $(jack_check_timestamp)
+else
 LOCAL_CHECKED_MODULE := $(full_classes_compiled_jar)
 endif
 endif
+endif
 
 #######################################
 include $(BUILD_SYSTEM)/base_rules.mk
@@ -630,9 +636,13 @@
 ifeq ($(LOCAL_JACK_ENABLED),incremental)
 $(LOCAL_INTERMEDIATE_TARGETS): \
 	PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-incremental
+$(noshrob_classes_jack): PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-noshrob-incremental
+$(jack_check_timestamp): PRIVATE_JACK_INCREMENTAL_DIR := $(intermediates.COMMON)/jack-check-incremental
 else
 $(LOCAL_INTERMEDIATE_TARGETS): \
 	PRIVATE_JACK_INCREMENTAL_DIR :=
+$(noshrob_classes_jack): PRIVATE_JACK_INCREMENTAL_DIR :=
+$(jack_check_timestamp): PRIVATE_JACK_INCREMENTAL_DIR :=
 endif
 
 ifdef full_classes_jar
@@ -665,6 +675,10 @@
         $(proto_java_sources_file_stamp) $(LOCAL_ADDITIONAL_DEPENDENCIES) $(LOCAL_JARJAR_RULES) \
         $(JACK)
 
+$(jack_check_timestamp): $(jack_all_deps)
+	@echo Checking build with Jack: $@
+	$(jack-check-java)
+
 ifeq ($(LOCAL_IS_STATIC_JAVA_LIBRARY),true)
 $(full_classes_jack): $(jack_all_deps) | setup-jack-server
 	@echo Building with Jack: $@
@@ -702,11 +716,6 @@
 endif #LOCAL_IS_STATIC_JAVA_LIBRARY
 
 $(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) | setup-jack-server
 	@echo Building with Jack: $@
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 097d801..8dd1f00 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -304,6 +304,7 @@
 endif
 ifneq ($(full_classes_jack),)
 $(full_classes_jack): $(R_file_stamp)
+$(jack_check_timestamp): $(R_file_stamp)
 endif
 endif # LOCAL_JACK_ENABLED
 
diff --git a/core/static_java_library.mk b/core/static_java_library.mk
index d956124..8913ee4 100644
--- a/core/static_java_library.mk
+++ b/core/static_java_library.mk
@@ -130,6 +130,7 @@
 ifdef LOCAL_JACK_ENABLED
 $(noshrob_classes_jack): $(R_file_stamp)
 $(full_classes_jack): $(R_file_stamp)
+$(jack_check_timestamp): $(R_file_stamp)
 endif # LOCAL_JACK_ENABLED
 $(full_classes_compiled_jar): $(R_file_stamp)