--- a/net/minecraft/server/LootEntryAbstract.java
+++ b/net/minecraft/server/LootEntryAbstract.java
@@ -34,7 +34,16 @@
 
         public Serializer() {}
 
-        public final void serializeType(JsonObject jsonobject, T t0, JsonSerializationContext jsonserializationcontext) {}
+        // CraftBukkit start
+        @Override
+        public final void a(JsonObject jsonobject, T t0, JsonSerializationContext jsonserializationcontext) {
+            if (!org.apache.commons.lang3.ArrayUtils.isEmpty(t0.d)) {
+                jsonobject.add("conditions", jsonserializationcontext.serialize(t0.d));
+            }
+
+            this.serializeType(jsonobject, t0, jsonserializationcontext);
+        }
+        // CraftBukkit end
 
         @Override
         public final T a(JsonObject jsonobject, JsonDeserializationContext jsondeserializationcontext) {