diff --git a/common/main/weapon.h b/common/main/weapon.h
index 9548c5425..1aee60568 100644
--- a/common/main/weapon.h
+++ b/common/main/weapon.h
@@ -276,8 +276,7 @@ public:
 namespace dsx {
 //return which bomb will be dropped next time the bomb key is pressed
 #if defined(DXX_BUILD_DESCENT_I)
-
-static constexpr int which_bomb()
+static constexpr secondary_weapon_index_t which_bomb(const player_info &)
 {
 	return PROXIMITY_INDEX;
 }
@@ -298,7 +297,8 @@ static constexpr unsigned vulcan_ammo_scale(const unsigned v)
 	return (v * 0xcc180u) >> 16;
 }
 #elif defined(DXX_BUILD_DESCENT_II)
-int which_bomb(void);
+secondary_weapon_index_t which_bomb(player_info &player_info);
+secondary_weapon_index_t which_bomb(const player_info &player_info);
 
 static constexpr int weapon_index_uses_vulcan_ammo(const unsigned id)
 {
diff --git a/similar/main/gamecntl.cpp b/similar/main/gamecntl.cpp
index d34e97ba8..3e1266485 100644
--- a/similar/main/gamecntl.cpp
+++ b/similar/main/gamecntl.cpp
@@ -249,34 +249,47 @@ static void update_vcr_state(void)
 
 namespace dsx {
 #if defined(DXX_BUILD_DESCENT_II)
+
+namespace {
+
 //returns which bomb will be dropped next time the bomb key is pressed
-int which_bomb()
+template <typename T>
+secondary_weapon_index_t read_update_which_proximity_mine_to_use(T &player_info)
 {
-	auto &Objects = LevelUniqueObjectState.Objects;
-	auto &vmobjptr = Objects.vmptr;
 	//use the last one selected, unless there aren't any, in which case use
 	//the other if there are any
-	auto &player_info = get_local_plrobj().ctype.player_info;
 	auto &Secondary_last_was_super = player_info.Secondary_last_was_super;
 	const auto mask = 1 << PROXIMITY_INDEX;
 	const auto bomb = (Secondary_last_was_super & mask) ? SMART_MINE_INDEX : PROXIMITY_INDEX;
-
 	auto &secondary_ammo = player_info.secondary_ammo;
 	if (secondary_ammo[bomb])
 		/* Player has the requested bomb type available.  Use it. */
 		return bomb;
-	const auto alt_bomb = SMART_MINE_INDEX + PROXIMITY_INDEX - bomb;
+	const auto alt_bomb = static_cast<secondary_weapon_index_t>(SMART_MINE_INDEX + PROXIMITY_INDEX - bomb);
 	if (secondary_ammo[alt_bomb])
 	{
 		/* Player has the alternate bomb type, but not the requested
 		 * bomb type.  Switch.
 		 */
-		Secondary_last_was_super ^= mask;
+		if constexpr (!std::is_const<T>::value)
+			Secondary_last_was_super ^= mask;
 		return alt_bomb;
 	}
 	/* Player has no bombs of either type. */
 	return bomb;
 }
+
+}
+
+secondary_weapon_index_t which_bomb(const player_info &player_info)
+{
+	return read_update_which_proximity_mine_to_use(player_info);
+}
+
+secondary_weapon_index_t which_bomb(player_info &player_info)
+{
+	return read_update_which_proximity_mine_to_use(player_info);
+}
 #endif
 
 namespace {
diff --git a/similar/main/gauges.cpp b/similar/main/gauges.cpp
index 5f9968a13..23adee03c 100644
--- a/similar/main/gauges.cpp
+++ b/similar/main/gauges.cpp
@@ -1295,7 +1295,7 @@ static void show_bomb_count(grs_canvas &canvas, const player_info &player_info,
 		return;
 #endif
 
-	const auto bomb = which_bomb();
+	const auto bomb = which_bomb(player_info);
 	int count = player_info.secondary_ammo[bomb];
 
 	count = min(count,99);	//only have room for 2 digits - cheating give 200
diff --git a/similar/main/laser.cpp b/similar/main/laser.cpp
index 68c93a703..99553192e 100644
--- a/similar/main/laser.cpp
+++ b/similar/main/laser.cpp
@@ -2315,8 +2315,8 @@ void do_missile_firing(int drop_bomb)
 	fix fire_frame_overhead = 0;
 
 	auto &plrobj = get_local_plrobj();
-	const auto bomb = which_bomb();
 	auto &player_info = plrobj.ctype.player_info;
+	const auto bomb = which_bomb(player_info);
 	const auto weapon = drop_bomb ? bomb : player_info.Secondary_weapon;
 	assert(weapon < MAX_SECONDARY_WEAPONS);
 	auto &Next_missile_fire_time = player_info.Next_missile_fire_time;