diff --git a/bootanimation/Android.mk b/bootanimation/Android.mk
index 9526112..31c1de4 100644
--- a/bootanimation/Android.mk
+++ b/bootanimation/Android.mk
@@ -41,6 +41,13 @@
     endif
 endif
 
+ifeq ($(TARGET_SCREEN_WIDTH),)
+    $(error TARGET_SCREEN_WIDTH must be set)
+endif
+ifeq ($(TARGET_SCREEN_HEIGHT),)
+    $(error TARGET_SCREEN_HEIGHT must be set)
+endif
+
 include $(CLEAR_VARS)
 LOCAL_MODULE := bootanimation.zip
 LOCAL_MODULE_CLASS := ETC