diff --git a/core/Makefile b/core/Makefile
index 4b8b5d8..d3669f2 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -9,6 +9,8 @@
   FILE_NAME_TAG := $(BUILD_NUMBER)
 endif
 
+is_tests_build := $(filter tests,$(MAKECMDGOALS))
+
 # -----------------------------------------------------------------
 # Define rules to copy PRODUCT_COPY_FILES defined by the product.
 # PRODUCT_COPY_FILES contains words like <source file>:<dest file>.
@@ -741,10 +743,18 @@
 #
 
 INTERNAL_SYSTEMIMAGE_FILES := $(filter $(TARGET_OUT)/%, \
-	$(ALL_PREBUILT) \
-	$(ALL_COPIED_HEADERS) \
-	$(ALL_GENERATED_SOURCES) \
-	$(ALL_DEFAULT_INSTALLED_MODULES))
+    $(ALL_PREBUILT) \
+    $(ALL_COPIED_HEADERS) \
+    $(ALL_GENERATED_SOURCES) \
+    $(ALL_DEFAULT_INSTALLED_MODULES))
+
+ifdef is_tests_build
+# We don't want to install tests modules to the system partition
+# when building "tests", because now "tests" may be built in a user, userdebug
+# or eng build variant and we don't want to pollute the system partition.
+# INTERNAL_SYSTEMIMAGE_FILES += $(filter $(TARGET_OUT)/%, \
+#    $(tests_MODULES))
+endif
 
 FULL_SYSTEMIMAGE_DEPS := $(INTERNAL_SYSTEMIMAGE_FILES) $(INTERNAL_USERIMAGES_DEPS)
 # -----------------------------------------------------------------
@@ -888,6 +898,12 @@
 INTERNAL_USERDATAIMAGE_FILES := \
     $(filter $(TARGET_OUT_DATA)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
 
+# If we build "tests" at the same time, make sure $(tests_MODULES) get covered.
+ifdef is_tests_build
+INTERNAL_USERDATAIMAGE_FILES += \
+    $(filter $(TARGET_OUT_DATA)/%,$(tests_MODULES))
+endif
+
 userdataimage_intermediates := \
     $(call intermediates-dir-for,PACKAGING,userdata)
 BUILT_USERDATAIMAGE_TARGET := $(PRODUCT_OUT)/userdata.img
@@ -1208,6 +1224,7 @@
 # This is very similar to BUILT_TARGET_FILES_PACKAGE, but we
 # only grab DATA, and it's called "*-tests-*.zip".
 #
+ifdef is_tests_build
 name := $(TARGET_PRODUCT)
 ifeq ($(TARGET_BUILD_TYPE),debug)
   name := $(name)_debug
@@ -1222,8 +1239,8 @@
 # Depending on the images guarantees that the underlying
 # directories are up-to-date.
 $(BUILT_TESTS_ZIP_PACKAGE): \
-		$(INSTALLED_USERDATAIMAGE_TARGET) \
-		| $(ACP)
+    $(INSTALLED_USERDATAIMAGE_TARGET) \
+    | $(ACP)
 	@echo "Package test files: $@"
 	$(hide) rm -rf $@ $(zip_root)
 	$(hide) mkdir -p $(dir $@) $(zip_root)
@@ -1246,6 +1263,13 @@
           $(BUILT_USERDATAIMAGE_TARGET))
 endif
 
+.PHONY: tests
+tests: $(BUILT_TESTS_ZIP_PACKAGE)
+ifneq (,$(filter tests, $(MAKECMDGOALS)))
+$(call dist-for-goals, tests, $(BUILT_TESTS_ZIP_PACKAGE))
+endif
+endif  # is_tests_build
+
 # -----------------------------------------------------------------
 # A zip of the symbols directory.  Keep the full paths to make it
 # more obvious where these files came from.
diff --git a/core/main.mk b/core/main.mk
index 5604df2..0084a0b 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -183,7 +183,7 @@
 # Bring in dex_preopt.mk
 include $(BUILD_SYSTEM)/dex_preopt.mk
 
-ifneq ($(filter eng user userdebug tests,$(MAKECMDGOALS)),)
+ifneq ($(filter eng user userdebug,$(MAKECMDGOALS)),)
 $(info ***************************************************************)
 $(info ***************************************************************)
 $(info Don't pass '$(filter eng user userdebug tests,$(MAKECMDGOALS))' on \
@@ -797,8 +797,7 @@
 endif # droid in $(MAKECMDGOALS)
 
 
-.PHONY: droid tests
-tests: droidcore
+.PHONY: droid
 
 # phony target that include any targets in $(ALL_MODULES)
 .PHONY: all_modules