diff --git a/build.gradle b/build.gradle
index a024f44..65a20ca 100644
--- a/build.gradle
+++ b/build.gradle
@@ -111,9 +111,6 @@ jar {
                 attribute_map['FMLCorePluginContainsFMLMod'] = true
                 attribute_map['ForceLoadAsMod'] = project.gradle.startParameter.taskNames[0] == "build"
             }
-        }
-        if (project.use_mixins.toBoolean()) {
-            attribute_map['TweakClass'] = 'org.spongepowered.asm.launch.MixinTweaker'
         }
 		if (project.use_access_transformer.toBoolean()) {
             attribute_map['FMLAT'] = project.archives_base_name + '_at.cfg'