diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
index 58dec5f279..38dd35b3b1 100644
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -605,6 +605,7 @@ CommandCost CmdTimetableSeparation(TileIndex tile, DoCommandFlag flags, uint32 p
 			}
 			v2->ClearSeparation();
 			SetWindowDirty(WC_VEHICLE_TIMETABLE, v2->index);
+			SetWindowDirty(WC_SCHDISPATCH_SLOTS, v2->index);
 		}
 	}