diff --git a/core/java/com/android/internal/util/ArrayUtils.java b/core/java/com/android/internal/util/ArrayUtils.java
index 686e1fc..9d0be4b 100644
--- a/core/java/com/android/internal/util/ArrayUtils.java
+++ b/core/java/com/android/internal/util/ArrayUtils.java
@@ -40,6 +40,7 @@
 /**
  * Static utility methods for arrays that aren't already included in {@link java.util.Arrays}.
  */
+@android.ravenwood.annotation.RavenwoodKeepWholeClass
 public class ArrayUtils {
     private static final int CACHE_SIZE = 73;
     private static Object[] sCache = new Object[CACHE_SIZE];
@@ -48,35 +49,43 @@
 
     private ArrayUtils() { /* cannot be instantiated */ }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static byte[] newUnpaddedByteArray(int minLen) {
         return (byte[])VMRuntime.getRuntime().newUnpaddedArray(byte.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static char[] newUnpaddedCharArray(int minLen) {
         return (char[])VMRuntime.getRuntime().newUnpaddedArray(char.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
     public static int[] newUnpaddedIntArray(int minLen) {
         return (int[])VMRuntime.getRuntime().newUnpaddedArray(int.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static boolean[] newUnpaddedBooleanArray(int minLen) {
         return (boolean[])VMRuntime.getRuntime().newUnpaddedArray(boolean.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static long[] newUnpaddedLongArray(int minLen) {
         return (long[])VMRuntime.getRuntime().newUnpaddedArray(long.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static float[] newUnpaddedFloatArray(int minLen) {
         return (float[])VMRuntime.getRuntime().newUnpaddedArray(float.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     public static Object[] newUnpaddedObjectArray(int minLen) {
         return (Object[])VMRuntime.getRuntime().newUnpaddedArray(Object.class, minLen);
     }
 
+    @android.ravenwood.annotation.RavenwoodReplace
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
     @SuppressWarnings("unchecked")
     public static <T> T[] newUnpaddedArray(Class<T> clazz, int minLen) {
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodClassLoadHook.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodClassLoadHook.java
similarity index 96%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodClassLoadHook.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodClassLoadHook.java
index 76964a7..7dc197e 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodClassLoadHook.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodClassLoadHook.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.TYPE;
 
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodKeep.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeep.java
similarity index 96%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodKeep.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeep.java
index ddf65dc..1d31579 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodKeep.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeep.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.CONSTRUCTOR;
 import static java.lang.annotation.ElementType.FIELD;
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodWholeClassKeep.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeepWholeClass.java
similarity index 93%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodWholeClassKeep.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeepWholeClass.java
index d7ef7f5..d2c77c1 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodWholeClassKeep.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodKeepWholeClass.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.CONSTRUCTOR;
 import static java.lang.annotation.ElementType.FIELD;
@@ -35,5 +35,5 @@
  */
 @Target({TYPE, FIELD, METHOD, CONSTRUCTOR})
 @Retention(RetentionPolicy.CLASS)
-public @interface RavenwoodWholeClassKeep {
+public @interface RavenwoodKeepWholeClass {
 }
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodNativeSubstitutionClass.java
similarity index 96%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodNativeSubstitutionClass.java
index 8cdc1ff..4b9cf85 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodNativeSubstitutionClass.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.TYPE;
 
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodRemove.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodRemove.java
similarity index 96%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodRemove.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodRemove.java
index 759c918..6727327 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodRemove.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodRemove.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.CONSTRUCTOR;
 import static java.lang.annotation.ElementType.FIELD;
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodReplace.java
similarity index 83%
copy from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java
copy to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodReplace.java
index 8cdc1ff..a920f63 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodNativeSubstitutionClass.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodReplace.java
@@ -13,9 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
-import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.ElementType.METHOD;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -29,8 +29,7 @@
  *
  * @hide
  */
-@Target({TYPE})
+@Target({METHOD})
 @Retention(RetentionPolicy.CLASS)
-public @interface RavenwoodNativeSubstitutionClass {
-    String value();
+public @interface RavenwoodReplace {
 }
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodThrow.java b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodThrow.java
similarity index 96%
rename from ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodThrow.java
rename to ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodThrow.java
index de3dd04..a234a9b 100644
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodThrow.java
+++ b/ravenwood/annotations-src/android/ravenwood/annotation/RavenwoodThrow.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package android.ravenwood.annotations;
+package android.ravenwood.annotation;
 
 import static java.lang.annotation.ElementType.CONSTRUCTOR;
 import static java.lang.annotation.ElementType.METHOD;
diff --git a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodSubstitute.java b/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodSubstitute.java
deleted file mode 100644
index 5a0a8f4..0000000
--- a/ravenwood/annotations-src/android/ravenwood/annotations/RavenwoodSubstitute.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright (C) 2023 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package android.ravenwood.annotations;
-
-import static java.lang.annotation.ElementType.METHOD;
-
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * THIS ANNOTATION IS EXPERIMENTAL. REACH OUT TO g/ravenwood BEFORE USING IT, OR YOU HAVE ANY
- * QUESTIONS ABOUT IT.
- *
- * TODO: Javadoc
- *
- * @hide
- */
-@Target({METHOD})
-@Retention(RetentionPolicy.CLASS)
-public @interface RavenwoodSubstitute {
-    // TODO We should add "_host" as default. We're not doing it yet, because extractign the default
-    // value with ASM doesn't seem trivial. (? not sure.)
-    String suffix();
-}
diff --git a/ravenwood/framework-minus-apex-ravenwood-policies.txt b/ravenwood/framework-minus-apex-ravenwood-policies.txt
index 48c0a2d..48d5722 100644
--- a/ravenwood/framework-minus-apex-ravenwood-policies.txt
+++ b/ravenwood/framework-minus-apex-ravenwood-policies.txt
@@ -76,16 +76,6 @@
 class android.util.UtilConfig stubclass
 
 # Internals
-class com.android.internal.util.ArrayUtils stubclass
-    method newUnpaddedByteArray (I)[B @newUnpaddedByteArray$ravenwood
-    method newUnpaddedCharArray (I)[C @newUnpaddedCharArray$ravenwood
-    method newUnpaddedIntArray (I)[I @newUnpaddedIntArray$ravenwood
-    method newUnpaddedBooleanArray (I)[Z @newUnpaddedBooleanArray$ravenwood
-    method newUnpaddedLongArray (I)[J @newUnpaddedLongArray$ravenwood
-    method newUnpaddedFloatArray (I)[F @newUnpaddedFloatArray$ravenwood
-    method newUnpaddedObjectArray (I)[Ljava/lang/Object; @newUnpaddedObjectArray$ravenwood
-    method newUnpaddedArray (Ljava/lang/Class;I)[Ljava/lang/Object; @newUnpaddedArray$ravenwood
-
 class com.android.internal.util.GrowingArrayUtils stubclass
 class com.android.internal.util.LineBreakBufferedWriter stubclass
 class com.android.internal.util.Preconditions stubclass
diff --git a/ravenwood/ravenwood-annotation-allowed-classes.txt b/ravenwood/ravenwood-annotation-allowed-classes.txt
index 0811f90..c6dd6e3 100644
--- a/ravenwood/ravenwood-annotation-allowed-classes.txt
+++ b/ravenwood/ravenwood-annotation-allowed-classes.txt
@@ -1,2 +1,3 @@
 # Only classes listed here can use the Ravenwood annotations.
 
+com.android.internal.util.ArrayUtils
diff --git a/ravenwood/ravenwood-standard-options.txt b/ravenwood/ravenwood-standard-options.txt
index 6e1384f..4b07ef6 100644
--- a/ravenwood/ravenwood-standard-options.txt
+++ b/ravenwood/ravenwood-standard-options.txt
@@ -16,22 +16,22 @@
 # Standard annotations.
 # Note, each line is a single argument, so we need newlines after each `--xxx-annotation`.
 --keep-annotation
-    android.ravenwood.annotations.RavenwoodKeep
+    android.ravenwood.annotation.RavenwoodKeep
 
 --keep-class-annotation
-    android.ravenwood.annotations.RavenwoodWholeClassKeep
+    android.ravenwood.annotation.RavenwoodKeepWholeClass
 
 --throw-annotation
-    android.ravenwood.annotations.RavenwoodThrow
+    android.ravenwood.annotation.RavenwoodThrow
 
 --remove-annotation
-    android.ravenwood.annotations.RavenwoodRemove
+    android.ravenwood.annotation.RavenwoodRemove
 
 --substitute-annotation
-    android.ravenwood.annotations.RavenwoodSubstitute
+    android.ravenwood.annotation.RavenwoodReplace
 
 --native-substitute-annotation
-    android.ravenwood.annotations.RavenwoodNativeSubstitutionClass
+    android.ravenwood.annotation.RavenwoodNativeSubstitutionClass
 
 --class-load-hook-annotation
-    android.ravenwood.annotations.RavenwoodClassLoadHook
+    android.ravenwood.annotation.RavenwoodClassLoadHook
diff --git a/tools/hoststubgen/hoststubgen/src/com/android/hoststubgen/filters/AnnotationBasedFilter.kt b/tools/hoststubgen/hoststubgen/src/com/android/hoststubgen/filters/AnnotationBasedFilter.kt
index eda6761..ee67f0f 100644
--- a/tools/hoststubgen/hoststubgen/src/com/android/hoststubgen/filters/AnnotationBasedFilter.kt
+++ b/tools/hoststubgen/hoststubgen/src/com/android/hoststubgen/filters/AnnotationBasedFilter.kt
@@ -377,7 +377,7 @@
                         throw HostStubGenInternalException("Policy $policy shouldn't show up here")
                     }
 
-                    val suffix = getAnnotationField(an, "suffix") ?: return@let
+                    val suffix = getAnnotationField(an, "suffix", false) ?: "\$ravenwood"
                     val renameFrom = mn.name + suffix
                     val renameTo = mn.name
 
@@ -405,10 +405,11 @@
     /**
      * Return the (String) value of 'value' parameter from an annotation.
      */
-    private fun getAnnotationField(an: AnnotationNode, name: String): String? {
+    private fun getAnnotationField(an: AnnotationNode, name: String,
+                                   required: Boolean = true): String? {
         try {
             val suffix = findAnnotationValueAsString(an, name)
-            if (suffix == null) {
+            if (suffix == null && required) {
                 errors.onErrorFound("Annotation \"${an.desc}\" must have field $name")
             }
             return suffix
@@ -438,4 +439,4 @@
             return ret
         }
     }
-}
\ No newline at end of file
+}