diff --git a/Source/missiles.cpp b/Source/missiles.cpp
index e525fade7..19751c17c 100644
--- a/Source/missiles.cpp
+++ b/Source/missiles.cpp
@@ -3810,40 +3810,53 @@ void MI_Search(int i)
 	AutoMapShowItems = false;
 }
 
-void MI_LightningWallC(int i)
+bool GrowWall(int playerId, Point position, Point target, missile_id type, int spellLevel, int damage)
 {
-	int tx, ty;
+	int dp = dPiece[position.x][position.y];
+	assert(dp <= MAXTILES && dp >= 0);
 
-	missile[i]._mirange--;
-	int id = missile[i]._misource;
-	int lvl = (id > -1) ? plr[id]._pLevel : 0;
+	if (nMissileTable[dp] || !InDungeonBounds(target)) {
+		return false;
+	}
 
-	int dmg = 16 * (GenerateRnd(10) + GenerateRnd(10) + lvl + 2);
+	AddMissile(position, position, plr[playerId]._pdir, type, TARGET_BOTH, playerId, damage, spellLevel);
+	return true;
+}
+
+void MI_LightningWallC(int i)
+{
+	missile[i]._mirange--;
 	if (missile[i]._mirange == 0) {
 		missile[i]._miDelFlag = true;
 		return;
 	}
 
-	int dp = dPiece[missile[i]._miVar1][missile[i]._miVar2];
-	assert(dp <= MAXTILES && dp >= 0);
-	Point t = Point { missile[i]._miVar1, missile[i]._miVar2 } + (Direction)missile[i]._miVar3;
-	if (!nMissileTable[dp] && missile[i]._miVar8 == 0 && InDungeonBounds(t)) {
-		AddMissile({ missile[i]._miVar1, missile[i]._miVar2 }, { missile[i]._miVar1, missile[i]._miVar2 }, plr[id]._pdir, MIS_LIGHTWALL, TARGET_BOTH, id, dmg, missile[i]._mispllvl);
-		missile[i]._miVar1 = t.x;
-		missile[i]._miVar2 = t.y;
-	} else {
-		missile[i]._miVar8 = 1;
+	int id = missile[i]._misource;
+	int lvl = (id > -1) ? plr[id]._pLevel : 0;
+	int dmg = 16 * (GenerateRnd(10) + GenerateRnd(10) + lvl + 2);
+
+	{
+		Point position = { missile[i]._miVar1, missile[i]._miVar2 };
+		Point target = position + static_cast<Direction>(missile[i]._miVar3);
+
+		if (missile[i]._miVar8 == 0 && GrowWall(id, position, target, MIS_LIGHTWALL, missile[i]._mispllvl, dmg)) {
+			missile[i]._miVar1 = target.x;
+			missile[i]._miVar2 = target.y;
+		} else {
+			missile[i]._miVar8 = 1;
+		}
 	}
 
-	dp = dPiece[missile[i]._miVar5][missile[i]._miVar6];
-	assert(dp <= MAXTILES && dp >= 0);
-	t = Point { missile[i]._miVar5, missile[i]._miVar6 } + (Direction)missile[i]._miVar4;
-	if (!nMissileTable[dp] && missile[i]._miVar7 == 0 && InDungeonBounds(t)) {
-		AddMissile({ missile[i]._miVar5, missile[i]._miVar6 }, { missile[i]._miVar5, missile[i]._miVar6 }, plr[id]._pdir, MIS_LIGHTWALL, TARGET_BOTH, id, dmg, missile[i]._mispllvl);
-		missile[i]._miVar5 = t.x;
-		missile[i]._miVar6 = t.y;
-	} else {
-		missile[i]._miVar7 = 1;
+	{
+		Point position = { missile[i]._miVar5, missile[i]._miVar6 };
+		Point target = position + static_cast<Direction>(missile[i]._miVar4);
+
+		if (missile[i]._miVar7 == 0 && GrowWall(id, position, target, MIS_LIGHTWALL, missile[i]._mispllvl, dmg)) {
+			missile[i]._miVar5 = target.x;
+			missile[i]._miVar6 = target.y;
+		} else {
+			missile[i]._miVar7 = 1;
+		}
 	}
 }
 
@@ -4504,35 +4517,36 @@ void MI_Fireman(int i)
 
 void MI_FirewallC(int i)
 {
-	int dp, tx, ty;
-
 	missile[i]._mirange--;
-	int id = missile[i]._misource;
 	if (missile[i]._mirange == 0) {
 		missile[i]._miDelFlag = true;
 		return;
 	}
 
-	int dp = dPiece[missile[i]._miVar1][missile[i]._miVar2];
-	assert(dp <= MAXTILES && dp >= 0);
-	Point t = Point { missile[i]._miVar1, missile[i]._miVar2 } + (Direction)missile[i]._miVar3;
-	if (!nMissileTable[dp] && missile[i]._miVar8 == 0 && InDungeonBounds(t)) {
-		AddMissile({ missile[i]._miVar1, missile[i]._miVar2 }, { missile[i]._miVar1, missile[i]._miVar2 }, plr[id]._pdir, MIS_FIREWALL, TARGET_BOTH, id, 0, missile[i]._mispllvl);
-		missile[i]._miVar1 = t.x;
-		missile[i]._miVar2 = t.y;
-	} else {
-		missile[i]._miVar8 = 1;
+	int id = missile[i]._misource;
+
+	{
+		Point position = { missile[i]._miVar1, missile[i]._miVar2 };
+		Point target = position + static_cast<Direction>(missile[i]._miVar3);
+
+		if (missile[i]._miVar8 == 0 && GrowWall(id, position, target, MIS_FIREWALL, missile[i]._mispllvl, 0)) {
+			missile[i]._miVar1 = target.x;
+			missile[i]._miVar2 = target.y;
+		} else {
+			missile[i]._miVar8 = 1;
+		}
 	}
 
-	dp = dPiece[missile[i]._miVar5][missile[i]._miVar6];
-	assert(dp <= MAXTILES && dp >= 0);
-	t = Point { missile[i]._miVar5, missile[i]._miVar6 } + (Direction)missile[i]._miVar4;
-	if (!nMissileTable[dp] && missile[i]._miVar7 == 0 && InDungeonBounds(t)) {
-		AddMissile({ missile[i]._miVar5, missile[i]._miVar6 }, { missile[i]._miVar5, missile[i]._miVar6 }, plr[id]._pdir, MIS_FIREWALL, TARGET_BOTH, id, 0, missile[i]._mispllvl);
-		missile[i]._miVar5 = t.x;
-		missile[i]._miVar6 = t.y;
-	} else {
-		missile[i]._miVar7 = 1;
+	{
+		Point position = { missile[i]._miVar5, missile[i]._miVar6 };
+		Point target = position + static_cast<Direction>(missile[i]._miVar4);
+
+		if (missile[i]._miVar7 == 0 && GrowWall(id, position, target, MIS_FIREWALL, missile[i]._mispllvl, 0)) {
+			missile[i]._miVar5 = target.x;
+			missile[i]._miVar6 = target.y;
+		} else {
+			missile[i]._miVar7 = 1;
+		}
 	}
 }