--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -2464,6 +2464,46 @@
 		}
 	}
 
+	/* Move the signal variant back up one bit for PBS. We don't convert the old PBS
+	 * format here, as an old layout wouldn't work properly anyway. To be safe, we
+	 * clear any possible PBS reservations as well. */
+	if (CheckSavegameVersion(100)) {
+		for (TileIndex t = 0; t < map_size; t++) {
+			switch (GetTileType(t)) {
+				case MP_RAILWAY:
+					if (HasSignals(t)) {
+						/* move the signal variant */
+						SetSignalVariant(t, TRACK_UPPER, HasBit(_m[t].m2, 2) ? SIG_SEMAPHORE : SIG_ELECTRIC);
+						SetSignalVariant(t, TRACK_LOWER, HasBit(_m[t].m2, 6) ? SIG_SEMAPHORE : SIG_ELECTRIC);
+						ClrBit(_m[t].m2, 2);
+						ClrBit(_m[t].m2, 6);
+					}
+
+					/* Clear PBS reservation on track */
+					if (IsRailDepot(t) ||IsRailWaypoint(t)) {
+						SetDepotWaypointReservation(t, false);
+					} else {
+						SetTrackReservation(t, TRACK_BIT_NONE);
+					}
+					break;
+
+				case MP_ROAD: /* Clear PBS reservation on crossing */
+					if (IsLevelCrossing(t)) SetCrossingReservation(t, false);
+					break;
+
+				case MP_STATION: /* Clear PBS reservation on station */
+					if (IsRailwayStation(t)) SetRailwayStationReservation(t, false);
+					break;
+
+				case MP_TUNNELBRIDGE: /* Clear PBS reservation on tunnels/birdges */
+					if (GetTunnelBridgeTransportType(t) == TRANSPORT_RAIL) SetTunnelBridgeReservation(t, false);
+					break;
+
+				default: break;
+			}
+		}
+	}
+
 	GamelogPrintDebug(1);
 
 	return InitializeWindowsAndCaches();