diff --git a/core/apidiff.mk b/core/apidiff.mk
index 3307469..1a7467d 100644
--- a/core/apidiff.mk
+++ b/core/apidiff.mk
@@ -47,18 +47,18 @@
 
 ifneq ($(LOCAL_SDK_VERSION),)
   ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),current)
-	# Use android_stubs_current if LOCAL_SDK_VERSION is current and no TARGET_BUILD_APPS.
-	LOCAL_JAVA_LIBRARIES := android_stubs_current $(LOCAL_JAVA_LIBRARIES)
-	$(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_stubs_current)
+    # Use android_stubs_current if LOCAL_SDK_VERSION is current and no TARGET_BUILD_APPS.
+    LOCAL_JAVA_LIBRARIES := android_stubs_current $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_stubs_current)
   else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),system_current)
-	LOCAL_JAVA_LIBRARIES := android_system_stubs_current $(LOCAL_JAVA_LIBRARIES)
-	$(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_system_stubs_current)
+    LOCAL_JAVA_LIBRARIES := android_system_stubs_current $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_system_stubs_current)
   else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),test_current)
-	LOCAL_JAVA_LIBRARIES := android_test_stubs_current $(LOCAL_JAVA_LIBRARIES)
-	$(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_test_stubs_current)
+    LOCAL_JAVA_LIBRARIES := android_test_stubs_current $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_test_stubs_current)
   else
-	LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
-	$(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
+    LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
   endif
 else
   LOCAL_JAVA_LIBRARIES := core-oj core-libart ext framework $(LOCAL_JAVA_LIBRARIES)