diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 14b9a85884..9280e2b67c 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -6974,8 +6974,10 @@ static void HandleVarAction2OptimisationPasses()
 				}
 			});
 			handle_group(group->default_group);
-			for (const auto &range : group->ranges) {
+			group->default_group = PruneTargetSpriteGroup(group->default_group);
+			for (auto &range : group->ranges) {
 				handle_group(range.group);
+				range.group = PruneTargetSpriteGroup(range.group);
 			}
 		}