diff --git a/src/Bullet.cpp b/src/Bullet.cpp
index c7157f85..9331717c 100644
--- a/src/Bullet.cpp
+++ b/src/Bullet.cpp
@@ -1640,7 +1640,10 @@ void ActBullet_Edge(BULLET *bul)
 				bul->damage = 1;
 
 			if (bul->ani_no > 4)
+			{
 				bul->cond = 0;
+				return;	// Prevent UB at rc[bul->ani_no] when bul->ani_no == 5
+			}
 
 			break;
 	}
diff --git a/src/Caret.cpp b/src/Caret.cpp
index 308ac5a9..df9686b4 100644
--- a/src/Caret.cpp
+++ b/src/Caret.cpp
@@ -73,7 +73,10 @@ void ActCaret01(CARET *crt)
 	{
 		crt->ani_wait = 0;
 		if (++crt->ani_no > 3)
+		{
 			crt->cond = 0;
+			return;	// Prevent UB at rc[crt->ani_no] when crt->ani_no == 4
+		}
 	}
 
 	// Note that 'crt->ani_no' can exceed the size of 'rcLeft' and 'rcRight'
@@ -247,7 +250,10 @@ void ActCaret07(CARET *crt)
 		crt->ani_wait = 0;
 
 		if (++crt->ani_no > 6)
+		{
 			crt->cond = 0;
+			return;	// Prevent UB at rcLeft[crt->ani_no] when crt->ani_no == 6
+		}
 	}
 
 	// Note that 'crt->ani_no' can exceed the size of rcLeft
@@ -453,7 +459,10 @@ void ActCaret14(CARET *crt)
 		crt->ani_wait = 0;
 
 		if (++crt->ani_no > 4)
+		{
 			crt->cond = 0;
+			return;	// Prevent UB at rect[crt->ani_no] when crt->ani_no == 5
+		}
 	}
 
 	// Note that 'crt->ani_no' can exceed the size of 'rect'
@@ -475,7 +484,10 @@ void ActCaret15(CARET *crt)
 		crt->ani_wait = 0;
 
 		if (++crt->ani_no > 3)
+		{
 			crt->cond = 0;
+			return;	// Prevent UB at rcLeft[crt->ani_no] when crt->ani_no == 4
+		}
 	}
 
 	// Note that 'crt->ani_no' can exceed the size of 'rcLeft'
diff --git a/src/NpcAct120.cpp b/src/NpcAct120.cpp
index 68e37bf5..c29ad5a1 100644
--- a/src/NpcAct120.cpp
+++ b/src/NpcAct120.cpp
@@ -585,7 +585,10 @@ void ActNpc127(NPCHAR *npc)
 	{
 		npc->ani_wait = 0;
 		if (++npc->ani_no > 2)
+		{
 			npc->cond = 0;
+			return; // Prevent UB at rc[npc->ani_no] when npc->ani_no == 3
+		}
 	}
 
 	// Note that 'npc->ani_no' can exceed the size of 'rcH' and 'rcV'
@@ -648,7 +651,10 @@ void ActNpc128(NPCHAR *npc)
 	}
 
 	if (++npc->ani_no > 4)
+	{
 		npc->cond = 0;
+		return;	// Prevent UB at rc[npc->ani_no] when npc->ani_no == 5
+	}
 
 	// Note that 'npc->ani_no' can exceed the bounds of 'rcLeft', 'rcUp', 'rcRight' and 'rcDown'
 
@@ -701,7 +707,10 @@ void ActNpc129(NPCHAR *npc)
 		npc->ani_wait = 0;
 
 		if (++npc->ani_no > 2)
+		{
 			npc->cond = 0;
+			return;	// Prevent UB at rect[(npc->direct * 3) + npc->ani_no] when npc->direct == 5 and npc->ani_no == 3
+		}
 	}
 
 	npc->y += npc->ym;
diff --git a/src/NpcAct140.cpp b/src/NpcAct140.cpp
index f186a992..49986a29 100644
--- a/src/NpcAct140.cpp
+++ b/src/NpcAct140.cpp
@@ -753,6 +753,7 @@ void ActNpc146(NPCHAR *npc)
 			{
 				SetDestroyNpChar(npc->x, npc->y, 0x1000, 8);
 				npc->cond = 0;
+				return;	// Prevent UB at rect[npc->ani_no] when npc->ani_no == 5
 			}
 
 			break;
diff --git a/src/NpcAct180.cpp b/src/NpcAct180.cpp
index 372b3563..98d90d26 100644
--- a/src/NpcAct180.cpp
+++ b/src/NpcAct180.cpp
@@ -1426,7 +1426,10 @@ void ActNpc199(NPCHAR *npc)
 	}
 
 	if (npc->ani_no > 4)
+	{
 		npc->cond = 0;
+		return;	// Prevent UB at rect[npc->ani_no] when npc->ani_no == 5
+	}
 
 	npc->x += npc->xm;
 	npc->y += npc->ym;