--- a/net/minecraft/world/entity/monster/EntityZombieVillager.java
+++ b/net/minecraft/world/entity/monster/EntityZombieVillager.java
@@ -51,6 +51,13 @@
 import net.minecraft.world.level.block.state.IBlockData;
 import org.slf4j.Logger;
 
+// CraftBukkit start
+import net.minecraft.server.MinecraftServer;
+import org.bukkit.entity.ZombieVillager;
+import org.bukkit.event.entity.CreatureSpawnEvent;
+import org.bukkit.event.entity.EntityTransformEvent;
+// CraftBukkit end
+
 public class EntityZombieVillager extends EntityZombie implements VillagerDataHolder {
 
     private static final Logger LOGGER = LogUtils.getLogger();
@@ -68,6 +75,7 @@
     @Nullable
     private MerchantRecipeList tradeOffers;
     private int villagerXp;
+    private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field
 
     public EntityZombieVillager(EntityTypes<? extends EntityZombieVillager> entitytypes, World world) {
         super(entitytypes, world);
@@ -86,7 +94,7 @@
     @Override
     public void addAdditionalSaveData(NBTTagCompound nbttagcompound) {
         super.addAdditionalSaveData(nbttagcompound);
-        DataResult dataresult = VillagerData.CODEC.encodeStart(DynamicOpsNBT.INSTANCE, this.getVillagerData());
+        DataResult<NBTBase> dataresult = VillagerData.CODEC.encodeStart(DynamicOpsNBT.INSTANCE, this.getVillagerData()); // CraftBukkit - decompile error
         Logger logger = EntityZombieVillager.LOGGER;
 
         Objects.requireNonNull(logger);
@@ -121,7 +129,7 @@
         }
 
         if (nbttagcompound.contains("Offers")) {
-            DataResult dataresult1 = MerchantRecipeList.CODEC.parse(this.registryAccess().createSerializationContext(DynamicOpsNBT.INSTANCE), nbttagcompound.get("Offers"));
+            DataResult<MerchantRecipeList> dataresult1 = MerchantRecipeList.CODEC.parse(this.registryAccess().createSerializationContext(DynamicOpsNBT.INSTANCE), nbttagcompound.get("Offers")); // CraftBukkit - decompile error
             Logger logger1 = EntityZombieVillager.LOGGER;
 
             Objects.requireNonNull(logger1);
@@ -148,6 +156,10 @@
     public void tick() {
         if (!this.level().isClientSide && this.isAlive() && this.isConverting()) {
             int i = this.getConversionProgress();
+            // CraftBukkit start - Use wall time instead of ticks for villager conversion
+            int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
+            i *= elapsedTicks;
+            // CraftBukkit end
 
             this.villagerConversionTime -= i;
             if (this.villagerConversionTime <= 0) {
@@ -156,6 +168,7 @@
         }
 
         super.tick();
+        this.lastTick = MinecraftServer.currentTick; // CraftBukkit
     }
 
     @Override
@@ -196,8 +209,10 @@
         this.conversionStarter = uuid;
         this.villagerConversionTime = i;
         this.getEntityData().set(EntityZombieVillager.DATA_CONVERTING_ID, true);
-        this.removeEffect(MobEffects.WEAKNESS);
-        this.addEffect(new MobEffect(MobEffects.DAMAGE_BOOST, i, Math.min(this.level().getDifficulty().getId() - 1, 0)));
+        // CraftBukkit start
+        this.removeEffect(MobEffects.WEAKNESS, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.CONVERSION);
+        this.addEffect(new MobEffect(MobEffects.DAMAGE_BOOST, i, Math.min(this.level().getDifficulty().getId() - 1, 0)), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.CONVERSION);
+        // CraftBukkit end
         this.level().broadcastEntityEvent(this, (byte) 16);
     }
 
@@ -214,12 +229,20 @@
     }
 
     private void finishConversion(WorldServer worldserver) {
-        EntityVillager entityvillager = (EntityVillager) this.convertTo(EntityTypes.VILLAGER, false);
+        // CraftBukkit start
+        EntityVillager entityvillager = (EntityVillager) this.convertTo(EntityTypes.VILLAGER, false, EntityTransformEvent.TransformReason.CURED, CreatureSpawnEvent.SpawnReason.CURED);
+        if (entityvillager == null) {
+            ((ZombieVillager) getBukkitEntity()).setConversionTime(-1); // SPIGOT-5208: End conversion to stop event spam
+            return;
+        }
+        // CraftBukkit end
 
         if (entityvillager != null) {
+            this.forceDrops = true; // CraftBukkit
             Iterator iterator = this.dropPreservedEquipment((itemstack) -> {
                 return !EnchantmentManager.has(itemstack, EnchantmentEffectComponents.PREVENT_ARMOR_CHANGE);
             }).iterator();
+            this.forceDrops = false; // CraftBukkit
 
             while (iterator.hasNext()) {
                 EnumItemSlot enumitemslot = (EnumItemSlot) iterator.next();
@@ -249,7 +272,7 @@
                 }
             }
 
-            entityvillager.addEffect(new MobEffect(MobEffects.CONFUSION, 200, 0));
+            entityvillager.addEffect(new MobEffect(MobEffects.CONFUSION, 200, 0), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.CONVERSION); // CraftBukkit
             if (!this.isSilent()) {
                 worldserver.levelEvent((EntityHuman) null, 1027, this.blockPosition(), 0);
             }