diff --git a/aircraft_gui.c b/aircraft_gui.c
index 72784b99ec..7fd25fdb6f 100644
--- a/aircraft_gui.c
+++ b/aircraft_gui.c
@@ -1142,7 +1142,7 @@ static void PlayerAircraftWndProc(Window *w, WindowEvent *e)
 		break;
 
 	case WE_DESTROY:
-		free(vl->sort_list);
+		free((void*)vl->sort_list);
 		break;
 
 	case WE_TICK: /* resort the list every 20 seconds orso (10 days) */
diff --git a/roadveh_gui.c b/roadveh_gui.c
index f047cd93ae..3607a67d10 100644
--- a/roadveh_gui.c
+++ b/roadveh_gui.c
@@ -1078,7 +1078,7 @@ static void PlayerRoadVehWndProc(Window *w, WindowEvent *e)
 		break;
 
 	case WE_DESTROY:
-		free(vl->sort_list);
+		free((void*)vl->sort_list);
 		break;
 
 	case WE_TICK: /* resort the list every 20 seconds orso (10 days) */
diff --git a/ship_gui.c b/ship_gui.c
index e8fd59c711..b2ed661ad0 100644
--- a/ship_gui.c
+++ b/ship_gui.c
@@ -1090,7 +1090,7 @@ static void PlayerShipsWndProc(Window *w, WindowEvent *e)
 		break;
 
 	case WE_DESTROY:
-		free(vl->sort_list);
+		free((void*)vl->sort_list);
 		break;
 
 	case WE_TICK: /* resort the list every 20 seconds orso (10 days) */
diff --git a/station_gui.c b/station_gui.c
index ab106fbc2d..8f4a45b8f5 100644
--- a/station_gui.c
+++ b/station_gui.c
@@ -232,7 +232,7 @@ static void SortStationsList(plstations_d *sl)
 
 	_internal_sort_order = sl->flags & SL_ORDER;
 	_last_station = NULL; // used for "cache" in namesorting
-	qsort(sl->sort_list, sl->list_length, sizeof(sl->sort_list[0]), _station_sorter[sl->sort_type]);
+	qsort((void*)sl->sort_list, sl->list_length, sizeof(sl->sort_list[0]), _station_sorter[sl->sort_type]);
 
 	sl->resort_timer = DAY_TICKS * PERIODIC_RESORT_DAYS;
 	sl->flags &= ~SL_RESORT;
diff --git a/train_gui.c b/train_gui.c
index b732e02a7c..fc17035622 100644
--- a/train_gui.c
+++ b/train_gui.c
@@ -1539,7 +1539,7 @@ static void PlayerTrainsWndProc(Window *w, WindowEvent *e)
 		break;
 
 	case WE_DESTROY:
-		free(vl->sort_list);
+		free((void*)vl->sort_list);
 		break;
 
 	case WE_TICK: /* resort the list every 20 seconds orso (10 days) */
diff --git a/vehicle_gui.c b/vehicle_gui.c
index bfe1adb62d..a1bf146a98 100644
--- a/vehicle_gui.c
+++ b/vehicle_gui.c
@@ -182,7 +182,7 @@ void SortVehicleList(vehiclelist_d *vl)
 	_internal_sort_order = vl->flags & VL_DESC;
 	_internal_name_sorter_id = STR_SV_TRAIN_NAME;
 	_last_vehicle = NULL; // used for "cache" in namesorting
-	qsort(vl->sort_list, vl->list_length, sizeof(vl->sort_list[0]),
+	qsort((void*)vl->sort_list, vl->list_length, sizeof(vl->sort_list[0]),
 		_vehicle_sorter[vl->sort_type]);
 
 	vl->resort_timer = DAY_TICKS * PERIODIC_RESORT_DAYS;