diff --git a/common/main/collide.h b/common/main/collide.h
index f017b9ccc..6c0218149 100644
--- a/common/main/collide.h
+++ b/common/main/collide.h
@@ -64,7 +64,13 @@ void drop_player_eggs(vobjptridx_t playerobj);
 #if defined(DXX_BUILD_DESCENT_II)
 void do_final_boss_frame(void);
 void do_final_boss_hacks(void);
-int check_volatile_wall(vobjptridx_t obj,vcsegptr_t seg,int sidenum);
+enum class volatile_wall_result : int8_t
+{
+	none = -1,
+	lava,
+	water,
+};
+volatile_wall_result check_volatile_wall(vobjptridx_t obj,vcsegptr_t seg,int sidenum);
 extern int	Final_boss_is_dead;
 #endif
 #endif
diff --git a/similar/main/collide.cpp b/similar/main/collide.cpp
index 075d74d68..693186cad 100644
--- a/similar/main/collide.cpp
+++ b/similar/main/collide.cpp
@@ -448,7 +448,7 @@ void scrape_player_on_wall(const vobjptridx_t obj, const vsegptridx_t hitseg, sh
 //see if wall is volatile or water
 //if volatile, cause damage to player
 //returns 1=lava, 2=water
-int check_volatile_wall(const vobjptridx_t obj, const vcsegptr_t seg, int sidenum)
+volatile_wall_result check_volatile_wall(const vobjptridx_t obj, const vcsegptr_t seg, int sidenum)
 {
 	Assert(obj->type==OBJ_PLAYER);
 
@@ -474,30 +474,28 @@ int check_volatile_wall(const vobjptridx_t obj, const vcsegptr_t seg, int sidenu
 			obj->mtype.phys_info.rotvel.z = (d_rand() - 16384)/2;
 		}
 
-		return (d>0)?1:2;
+		return (d > 0) ? volatile_wall_result::lava : volatile_wall_result::water;
 	}
 	else
 	 {
-		return 0;
+		return volatile_wall_result::none;
 	 }
 }
 
 //this gets called when an object is scraping along the wall
 void scrape_player_on_wall(const vobjptridx_t obj, const vsegptridx_t hitseg, short hitside, const vms_vector &hitpt)
 {
-	int type;
-
 	if (obj->type != OBJ_PLAYER || get_player_id(obj) != Player_num)
 		return;
 
-	if ((type=check_volatile_wall(obj,hitseg,hitside))!=0) {
+	const auto type = check_volatile_wall(obj, hitseg, hitside);
+	if (type != volatile_wall_result::none)
+	{
 		vms_vector	hit_dir;
 
 		if ((GameTime64 > Last_volatile_scrape_sound_time + F1_0/4) || (GameTime64 < Last_volatile_scrape_sound_time)) {
-			int sound = (type==1)?SOUND_VOLATILE_WALL_HISS:SOUND_SHIP_IN_WATER;
-
 			Last_volatile_scrape_sound_time = GameTime64;
-
+			const auto sound = (type == volatile_wall_result::lava) ? SOUND_VOLATILE_WALL_HISS : SOUND_SHIP_IN_WATER;
 			multi_digi_link_sound_to_pos(sound, hitseg, 0, hitpt, 0, F1_0);
 		}
 
diff --git a/similar/main/object.cpp b/similar/main/object.cpp
index 784617a7f..91e9f53c5 100644
--- a/similar/main/object.cpp
+++ b/similar/main/object.cpp
@@ -1745,30 +1745,39 @@ static void object_move_one(const vobjptridx_t obj)
 		}
 #if defined(DXX_BUILD_DESCENT_II)
 		{
-			int sidemask,under_lavafall=0;
-			static int lavafall_hiss_playing[MAX_PLAYERS]={0};
+			bool under_lavafall = false;
+			static array<bool, MAX_PLAYERS> lavafall_hiss_playing;
 
-			sidemask = get_seg_masks(obj->pos, vcsegptr(obj->segnum), obj->size).sidemask;
-			if (sidemask) {
-				int sidenum,bit,wall_num;
-	
-				for (sidenum=0,bit=1;sidenum<6;bit<<=1,sidenum++)
-					if ((sidemask & bit) && ((wall_num=Segments[obj->segnum].sides[sidenum].wall_num)!=-1) && Walls[wall_num].type==WALL_ILLUSION) {
-						int type;
-						if ((type=check_volatile_wall(obj,vsegptridx(obj->segnum),sidenum))!=0) {
-							int sound = (type==1)?SOUND_LAVAFALL_HISS:SOUND_SHIP_IN_WATERFALL;
+			auto &playing = lavafall_hiss_playing[get_player_id(obj)];
+			const auto &&segp = vcsegptr(obj->segnum);
+			if (const auto sidemask = get_seg_masks(obj->pos, segp, obj->size).sidemask)
+			{
+				for (unsigned sidenum = 0; sidenum != MAX_SIDES_PER_SEGMENT; ++sidenum)
+				{
+					if (!(sidemask & (1 << sidenum)))
+						continue;
+					const auto wall_num = segp->sides[sidenum].wall_num;
+					if (wall_num != wall_none && Walls[wall_num].type == WALL_ILLUSION)
+					{
+						const auto type = check_volatile_wall(obj, segp, sidenum);
+						if (type != volatile_wall_result::none)
+						{
 							under_lavafall = 1;
-							if (!lavafall_hiss_playing[get_player_id(obj)])
+							if (!playing)
 							{
-								lavafall_hiss_playing[get_player_id(obj)] = 1;
+								playing = 1;
+								const auto sound = (type == volatile_wall_result::lava) ? SOUND_LAVAFALL_HISS : SOUND_SHIP_IN_WATERFALL;
 								digi_link_sound_to_object3( sound, obj, 1, F1_0, vm_distance{i2f(256)}, -1, -1);
+								break;
 							}
 						}
 					}
+				}
 			}
 	
-			if (!under_lavafall && lavafall_hiss_playing[get_player_id(obj)]) {
-				lavafall_hiss_playing[get_player_id(obj)] = 0;
+			if (!under_lavafall && playing)
+			{
+				playing = 0;
 				digi_kill_sound_linked_to_object( obj);
 			}
 		}