diff --git a/build.gradle.kts b/build.gradle.kts
index 35a0b1a..e3be762 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -55,7 +55,7 @@ taboolib {
             isSkipKotlinRelocate =true
             isSkipKotlin = true
         }
-        taboolib = "6.1.1-beta17"
+        taboolib = "6.1.1"
     }
 }
 
diff --git a/src/main/kotlin/com/skillw/attsystem/internal/feature/realizer/vanilla/VanillaAttTaskBuilder.kt b/src/main/kotlin/com/skillw/attsystem/internal/feature/realizer/vanilla/VanillaAttTaskBuilder.kt
index ba070c5..c2fa6e3 100644
--- a/src/main/kotlin/com/skillw/attsystem/internal/feature/realizer/vanilla/VanillaAttTaskBuilder.kt
+++ b/src/main/kotlin/com/skillw/attsystem/internal/feature/realizer/vanilla/VanillaAttTaskBuilder.kt
@@ -38,11 +38,14 @@ internal open class VanillaAttTaskBuilder(key: String, val attribute: BukkitAttr
     private val valuesCache = WeakHashMap<UUID, Double>()
 
     protected fun changed(uuid: UUID, value: Double): Boolean =
-        valuesCache.run {
-            return if (get(uuid) != value) {
-                put(uuid, value)
+        synchronized(valuesCache) {
+            val current = valuesCache[uuid]
+            return if (current != value) {
+                valuesCache[uuid] = value
                 true
-            } else false
+            } else {
+                false
+            }
         }