diff --git a/source/blood/src/ai.cpp b/source/blood/src/ai.cpp
index f97515e41..e2ee1764c 100644
--- a/source/blood/src/ai.cpp
+++ b/source/blood/src/ai.cpp
@@ -121,7 +121,7 @@ void aiNewState(spritetype *pSprite, XSPRITE *pXSprite, AISTATE *pAIState)
         pAIState->enterFunc(pSprite, pXSprite);
 }
 
-bool isUmmune(spritetype* pSprite, int dmgType, int minScale) {
+bool isImmune(spritetype* pSprite, int dmgType, int minScale) {
 
     if (dmgType >= kDmgFall && dmgType < kDmgMax && pSprite->extra >= 0 && xsprite[pSprite->extra].locked != 1) {
         if (pSprite->type >= kThingBase && pSprite->type < kThingMax)
@@ -212,7 +212,7 @@ bool CanMove(spritetype *pSprite, int a2, int nAngle, int nRange)
         // It makes ignore danger if enemy immune to N damageType. As result Cerberus start acting like
         // in Blood 1.0 so it can move normally to player. It's up to you for adding rest of enemies here as
         // i don't think it will broke something in game.
-        if (!VanillaMode() && Crusher && isUmmune(pSprite, pXSector->damageType, 16)) return true;
+        if (!VanillaMode() && Crusher && isImmune(pSprite, pXSector->damageType, 16)) return true;
         fallthrough__;
     case kDudeZombieButcher:
     case kDudeSpiderBrown:
@@ -232,7 +232,7 @@ bool CanMove(spritetype *pSprite, int a2, int nAngle, int nRange)
     #ifdef NOONE_EXTENSIONS
     case kDudeModernCustom:
     case kDudeModernCustomBurning:
-        if ((Crusher && !nnExtIsUmmune(pSprite, pXSector->damageType)) || ((Water || Underwater) && !canSwim(pSprite))) return false;
+        if ((Crusher && !nnExtIsImmune(pSprite, pXSector->damageType)) || ((Water || Underwater) && !canSwim(pSprite))) return false;
         return true;
         fallthrough__;
     #endif
diff --git a/source/blood/src/aiunicult.cpp b/source/blood/src/aiunicult.cpp
index 319b85580..2027381e1 100644
--- a/source/blood/src/aiunicult.cpp
+++ b/source/blood/src/aiunicult.cpp
@@ -767,7 +767,7 @@ static void thinkChase( spritetype* pSprite, XSPRITE* pXSprite ) {
                                 VectorScan(pSprite, 0, 0, Cos(pSprite->ang) >> 16, Sin(pSprite->ang) >> 16, gDudeSlope[pSprite->extra], dist, 1);
                                 if (pXSprite->target == gHitInfo.hitsprite) break;
                                 
-                                bool immune = nnExtIsUmmune(pHSprite, gVectorData[curWeapon].dmgType);
+                                bool immune = nnExtIsImmune(pHSprite, gVectorData[curWeapon].dmgType);
                                 if (!(pXHSprite != NULL && (!immune || (immune && pHSprite->statnum == kStatThing && pXHSprite->Vector)) && !pXHSprite->locked)) {
 
                                     if ((approxDist(gHitInfo.hitx - pSprite->x, gHitInfo.hity - pSprite->y) <= 1500 && !blck)
@@ -853,7 +853,7 @@ static void thinkChase( spritetype* pSprite, XSPRITE* pXSprite ) {
                                     else if (hit == 3 && (failed = (pHSprite->statnum != kStatThing || pXHSprite == NULL || pXHSprite->locked)) == false) {
                                         // check also for damage resistance (all possible damages missile can use)
                                         for (int i = 0; i < kDmgMax; i++) {
-                                            if (gMissileInfoExtra[curWeapon - kMissileBase].dmgType[i] && (failed = nnExtIsUmmune(pHSprite, i)) == false)
+                                            if (gMissileInfoExtra[curWeapon - kMissileBase].dmgType[i] && (failed = nnExtIsImmune(pHSprite, i)) == false)
                                                 break;
                                         }
                                     }
diff --git a/source/blood/src/nnexts.cpp b/source/blood/src/nnexts.cpp
index 84e85d2ca..d6db55432 100644
--- a/source/blood/src/nnexts.cpp
+++ b/source/blood/src/nnexts.cpp
@@ -108,7 +108,7 @@ THINGINFO_EXTRA gThingInfoExtra[] = {
 // for actor.cpp
 //-------------------------------------------------------------------------
 
-bool nnExtIsUmmune(spritetype* pSprite, int dmgType, int minScale) {
+bool nnExtIsImmune(spritetype* pSprite, int dmgType, int minScale) {
 
     if (dmgType >= kDmgFall && dmgType < kDmgMax && pSprite->extra >= 0 && xsprite[pSprite->extra].locked != 1) {
         if (pSprite->type >= kThingBase && pSprite->type < kThingMax)
diff --git a/source/blood/src/nnexts.h b/source/blood/src/nnexts.h
index ef7197b6f..6bf3672d2 100644
--- a/source/blood/src/nnexts.h
+++ b/source/blood/src/nnexts.h
@@ -162,7 +162,7 @@ extern short gPhysSpritesCount;
 bool nnExtEraseModernStuff(spritetype* pSprite, XSPRITE* pXSprite);
 void nnExtInitModernStuff(bool bSaveLoad);
 void nnExtProcessSuperSprites(void);
-bool nnExtIsUmmune(spritetype* pSprite, int dmgType, int minScale = 16);
+bool nnExtIsImmune(spritetype* pSprite, int dmgType, int minScale = 16);
 int nnExtRandom(int a, int b);
 //  -------------------------------------------------------------------------   //
 spritetype* randomDropPickupObject(spritetype* pSprite, short prevItem);