diff --git a/src/industry.h b/src/industry.h
--- a/src/industry.h
+++ b/src/industry.h
@@ -81,6 +81,7 @@ enum IndustyBehaviour {
 	INDUSTRYBEH_AIRPLANE_ATTACKS      = 1 << 11, ///< can be exploded by a military airplane (oil refinery)
 	INDUSTRYBEH_CHOPPER_ATTACKS       = 1 << 12, ///< can be exploded by a military helicopter (factory)
 	INDUSTRYBEH_CAN_SUBSIDENCE        = 1 << 13, ///< can cause a subsidence (coal mine, shaft that collapses)
+	INDUSTRYBEH_CANCLOSE_LASTINSTANCE = 1 << 17, ///< Allow closing down the last instance of this type
 };