diff --git a/updater/Android.mk b/updater/Android.mk
index 1159d7b..897b9d7 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -7,10 +7,15 @@ updater_src_files := \
 	updater.c
 
 #
-# Build the device-side library
+# Build a statically-linked binary to include in OTA packages
 #
 include $(CLEAR_VARS)
 
+# Build only in eng, so we don't end up with a copy of this in /system
+# on user builds.  (TODO: find a better way to build device binaries
+# needed only for OTA packages.)
+LOCAL_MODULE_TAGS := eng
+
 LOCAL_SRC_FILES := $(updater_src_files)
 
 LOCAL_STATIC_LIBRARIES := libapplypatch libedify libmtdutils libminzip libz