diff --git a/src/main/kotlin/ru/dbotthepony/kstarbound/io/json/builder/BuilderAdapter.kt b/src/main/kotlin/ru/dbotthepony/kstarbound/io/json/builder/BuilderAdapter.kt
index 650b71fd..13421634 100644
--- a/src/main/kotlin/ru/dbotthepony/kstarbound/io/json/builder/BuilderAdapter.kt
+++ b/src/main/kotlin/ru/dbotthepony/kstarbound/io/json/builder/BuilderAdapter.kt
@@ -14,12 +14,15 @@ import com.google.gson.stream.JsonReader
 import com.google.gson.stream.JsonToken
 import com.google.gson.stream.JsonWriter
 import it.unimi.dsi.fastutil.objects.ObjectArraySet
+import it.unimi.dsi.fastutil.objects.ObjectLinkedOpenHashSet
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap
 import org.apache.logging.log4j.LogManager
 import ru.dbotthepony.kstarbound.Starbound
 import ru.dbotthepony.kstarbound.defs.util.flattenJsonElement
 import ru.dbotthepony.kstarbound.io.json.util.asReference
 import ru.dbotthepony.kstarbound.util.NotNullVar
+import java.util.concurrent.ConcurrentHashMap
 import kotlin.properties.Delegates
 import kotlin.reflect.KCallable
 import kotlin.reflect.KClass
@@ -349,12 +352,27 @@ class BuilderAdapter<T : Any> private constructor(
 
 	companion object : TypeAdapterFactory {
 		private val LOGGER = LogManager.getLogger()
+		private val declCache = Reference2ObjectOpenHashMap<KClass<*>, ArrayList<KMutableProperty1<*, *>>>()
 
 		private fun collectDecl(input: KClass<*>, output: MutableMap<String, KMutableProperty1<*, *>>) {
+			for (decl in collectDeclImpl(input)) {
+				output.putIfAbsent(decl.name, decl)
+			}
+		}
+
+		private fun collectDeclImpl(input: KClass<*>): ArrayList<KMutableProperty1<*, *>> {
+			val getValues = synchronized(declCache) { declCache[input] }
+
+			if (getValues != null) {
+				return getValues
+			}
+
+			val values = ObjectLinkedOpenHashSet<KMutableProperty1<*, *>>()
+
 			for (decl in input.declaredMembers) {
 				if (decl is KMutableProperty1<*, *>) {
 					decl.isAccessible = true
-					output.putIfAbsent(decl.name, decl)
+					values.add(decl)
 				}
 			}
 
@@ -362,9 +380,13 @@ class BuilderAdapter<T : Any> private constructor(
 				val classifier = parent.classifier
 
 				if (classifier is KClass<*> && !classifier.java.isInterface) {
-					collectDecl(classifier, output)
+					values.addAll(collectDeclImpl(classifier))
 				}
 			}
+
+			val list = ArrayList(values)
+			synchronized(declCache) { declCache.put(input, list) }
+			return list
 		}
 
 		override fun <T : Any> create(gson: Gson, type: TypeToken<T>): TypeAdapter<T>? {