diff --git a/src/force.h b/src/force.h
index f213200cf4..9be26bd2a7 100644
--- a/src/force.h
+++ b/src/force.h
@@ -41,9 +41,9 @@ enum {
 };
 
 enum {
-  CENTROID_SAME     = 0x00,
-  CENTROID_AVAIL    = 0x01,
-  CENTROID_NOTAVAIL = 0x02
+  CENTROID_SAME     = 0x01,
+  CENTROID_AVAIL    = 0x02,
+  CENTROID_NOTAVAIL = 0x04
 };
 
 class Force : protected Pointers {