diff --git a/common/main/endlevel.h b/common/main/endlevel.h
index ca8f75e40..83d2d0123 100644
--- a/common/main/endlevel.h
+++ b/common/main/endlevel.h
@@ -50,7 +50,7 @@ extern segnum_t exit_segnum;
 //called for each level to load & setup the exit sequence
 void load_endlevel_data(int level_num);
 
-extern int exit_modelnum, destroyed_exit_modelnum;
+extern unsigned exit_modelnum, destroyed_exit_modelnum;
 extern vms_matrix surface_orient;
 
 #endif
diff --git a/similar/main/bm.cpp b/similar/main/bm.cpp
index ab58b63c5..fdec04772 100644
--- a/similar/main/bm.cpp
+++ b/similar/main/bm.cpp
@@ -394,10 +394,10 @@ static void bm_free_extra_objbitmaps()
 
 static void bm_free_extra_models()
 {
-	while (N_polygon_models > N_D2_POLYGON_MODELS)
-		free_model(&Polygon_models[--N_polygon_models]);
-	while (N_polygon_models > exit_modelnum)
-		free_model(&Polygon_models[--N_polygon_models]);
+	auto base = std::min(N_D2_POLYGON_MODELS, exit_modelnum);
+	range_for (auto &p, partial_range(Polygon_models, base, N_polygon_models))
+		free_model(&p);
+	N_polygon_models = base;
 }
 
 //type==1 means 1.1, type==2 means 1.2 (with weapons)
diff --git a/similar/main/endlevel.cpp b/similar/main/endlevel.cpp
index c3efc4414..2b07cf91c 100644
--- a/similar/main/endlevel.cpp
+++ b/similar/main/endlevel.cpp
@@ -158,14 +158,14 @@ static grs_bitmap *satellite_bitmap;
 grs_bitmap *terrain_bitmap;	//!!*exit_bitmap,
 vms_vector satellite_pos,satellite_upvec;
 //!!grs_bitmap **exit_bitmap_list[1];
-int station_modelnum,exit_modelnum,destroyed_exit_modelnum;
+unsigned exit_modelnum,destroyed_exit_modelnum;
 
 static vms_vector station_pos{0xf8c4<<10,0x3c1c<<12,0x372<<10};
 
 #ifdef STATION_ENABLED
 static grs_bitmap *station_bitmap;
 grs_bitmap **station_bitmap_list[1];
-int station_modelnum;
+static unsigned station_modelnum;
 #endif
 
 vms_vector mine_exit_point;