--- a/net/minecraft/world/effect/PoisonMobEffect.java
+++ b/net/minecraft/world/effect/PoisonMobEffect.java
@@ -3,6 +3,7 @@
 import net.minecraft.world.entity.LivingEntity;
 
 class PoisonMobEffect extends MobEffect {
+
     protected PoisonMobEffect(MobEffectCategory category, int color) {
         super(category, color);
     }
@@ -10,7 +11,7 @@
     @Override
     public boolean applyEffectTick(LivingEntity entity, int amplifier) {
         if (entity.getHealth() > 1.0F) {
-            entity.hurt(entity.damageSources().magic(), 1.0F);
+            entity.hurt(entity.damageSources().poison(), 1.0F);  // CraftBukkit - DamageSource.MAGIC -> CraftEventFactory.POISON
         }
 
         return true;
@@ -18,7 +19,8 @@
 
     @Override
     public boolean shouldApplyEffectTickThisTick(int duration, int amplifier) {
-        int i = 25 >> amplifier;
-        return i <= 0 || duration % i == 0;
+        int k = 25 >> amplifier;
+
+        return k > 0 ? duration % k == 0 : true;
     }
 }
