diff --git a/game/world/objects/npc.cpp b/game/world/objects/npc.cpp
index add7c6a32..6cd16d300 100644
--- a/game/world/objects/npc.cpp
+++ b/game/world/objects/npc.cpp
@@ -2299,13 +2299,16 @@ void Npc::tickRegen(int32_t& v, const int32_t max, const int32_t chg, const uint
   uint64_t tick = owner.tickCount();
   if(tick<dt || chg==0)
     return;
-  int32_t time0 = int32_t(tick%1000);
-  int32_t time1 = time0+int32_t(dt);
-
-  int32_t val0 = (time0*chg)/1000;
-  int32_t val1 = (time1*chg)/1000;
+  // ATR_REGENERATE* is an interval: 1 point per 'chg' seconds.
+  // treating it as points-per-second made monsters in mods with hp-regeneration (L'Hiver)
+  // heal faster than the player can deal damage
+  const uint64_t period = uint64_t(std::abs(chg))*1000u;
+  const int32_t  step   = chg>0 ? 1 : -1;
+  const int32_t  n      = int32_t((tick%period+dt)/period);
+  if(n==0)
+    return;
 
-  int32_t nextV = std::max(0,std::min(v+val1-val0,max));
+  int32_t nextV = std::max(0,std::min(v+n*step,max));
   if(v!=nextV) {
     v = nextV;
     // check health, in case of negative chg
@@ -4669,7 +4672,10 @@ bool Npc::canRayHitPoint(const Tempest::Vec3 self, const Tempest::Vec3 pos, floa
     return !w->ray(self, pos).hasCol;
     }
 
-  float dx  = self.x-pos.x, dz=self.z-pos.z;
+  // measure view cone from npc position, not from head bone: in melee the head of an
+  // attacking monster dives into the target and the direction becomes numerical noise.
+  // L'Hiver anti-exploit scripts read this as "player ran away" and heal the monster
+  float dx  = x-pos.x, dz = z-pos.z;
   float dir = angleDir(dx,dz);
   float da  = float(M_PI)*(visual.viewDirection()-dir)/180.f;
   auto  ca  = angOverride > 0 ? std::cos(angOverride*M_PI/180.0) : ref;