diff --git a/gradle.properties b/gradle.properties
index 4fd396ddf..4e7653807 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -45,7 +45,7 @@ modGroup = com.cleanroommc.groovyscript
 # Version of your mod.
 # This field can be left empty if you want your mod's version to be determined by the latest git tag instead.
 modVersion = 1.0.1
-groovy_version = 4.0.13
+groovy_version = 4.0.21
 debug_use_examples_folder = true
 debug_run_ls = false
 
diff --git a/src/main/java/com/cleanroommc/groovyscript/core/mixin/groovy/Java8Mixin.java b/src/main/java/com/cleanroommc/groovyscript/core/mixin/groovy/Java8Mixin.java
index 326e208d1..15f631f84 100644
--- a/src/main/java/com/cleanroommc/groovyscript/core/mixin/groovy/Java8Mixin.java
+++ b/src/main/java/com/cleanroommc/groovyscript/core/mixin/groovy/Java8Mixin.java
@@ -4,6 +4,8 @@
 import net.minecraftforge.fml.relauncher.FMLLaunchHandler;
 import org.codehaus.groovy.ast.Parameter;
 import org.codehaus.groovy.ast.*;
+import org.codehaus.groovy.ast.expr.ConstantExpression;
+import org.codehaus.groovy.ast.stmt.ReturnStatement;
 import org.codehaus.groovy.vmplugin.v8.Java8;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Overwrite;
@@ -28,13 +30,6 @@ public abstract class Java8Mixin {
     @Shadow
     protected abstract ClassNode[] makeClassNodes(CompileUnit cu, Type[] types, Class<?>[] cls);
 
-    @Shadow
-    private static void setMethodDefaultValue(MethodNode mn, Method m) {
-    }
-
-    @Shadow
-    protected abstract GenericsType[] configureTypeVariable(TypeVariable<?>[] tvs);
-
     @Shadow
     protected abstract Annotation[][] getConstructorParameterAnnotations(Constructor<?> constructor);
 
@@ -47,6 +42,9 @@ private static void setMethodDefaultValue(MethodNode mn, Method m) {
     @Shadow
     protected abstract void makeRecordComponents(CompileUnit cu, ClassNode classNode, Class<?> clazz);
 
+    @Shadow
+    protected abstract GenericsType[] configureTypeParameters(TypeVariable<?>[] tp);
+
     /**
      * @author brachy84
      * @reason remapping minecraft fields and methods
@@ -72,10 +70,13 @@ public void configureClassNode(final CompileUnit compileUnit, final ClassNode cl
                 ClassNode[] exceptions = makeClassNodes(compileUnit, m.getGenericExceptionTypes(), m.getExceptionTypes());
                 String name = deobfMethods != null ? deobfMethods.getOrDefault(m.getName(), m.getName()) : m.getName();
                 MethodNode mn = new MethodNode(name, m.getModifiers(), ret, params, exceptions, null);
-                mn.setSynthetic(m.isSynthetic());
-                setMethodDefaultValue(mn, m);
                 setAnnotationMetaData(m.getAnnotations(), mn);
-                mn.setGenericsTypes(configureTypeVariable(m.getTypeParameters()));
+                if (true) { // TODO: GROOVY-10862
+                    mn.setAnnotationDefault(true);
+                    mn.setCode(new ReturnStatement(new ConstantExpression(m.getDefaultValue())));
+                }
+                mn.setGenericsTypes(configureTypeParameters(m.getTypeParameters()));
+                mn.setSynthetic(m.isSynthetic());
                 classNode.addMethod(mn);
             }
             Constructor<?>[] constructors = clazz.getDeclaredConstructors();