diff --git a/policy/src/main/java/dev/cel/policy/CelPolicy.java b/policy/src/main/java/dev/cel/policy/CelPolicy.java
index 00c23e7e9..9980d0cad 100644
--- a/policy/src/main/java/dev/cel/policy/CelPolicy.java
+++ b/policy/src/main/java/dev/cel/policy/CelPolicy.java
@@ -60,6 +60,8 @@ public static Builder newBuilder() {
         .setMetadata(ImmutableMap.of());
   }
 
+  public abstract Builder toBuilder();
+
   /** Builder for {@link CelPolicy}. */
   @AutoValue.Builder
   public abstract static class Builder {