diff --git a/Android.mk b/Android.mk
index b3236505eb49e..7fa0e877b53aa 100644
--- a/Android.mk
+++ b/Android.mk
@@ -631,6 +631,7 @@ framework_docs_LOCAL_DROIDDOC_OPTIONS := \
     -since $(SRC_API_DIR)/18.txt 18 \
     -since $(SRC_API_DIR)/19.txt 19 \
     -since $(SRC_API_DIR)/20.txt 20 \
+    -since $(SRC_API_DIR)/21.txt 21 \
 		-werror -hide 111 -hide 113 \
 		-overview $(LOCAL_PATH)/core/java/overview.html