diff --git a/src/main/java/dev/lukebemish/codecextras/structured/KeyStoringInterpreter.java b/src/main/java/dev/lukebemish/codecextras/structured/KeyStoringInterpreter.java
index 3828ed2..7865e6a 100644
--- a/src/main/java/dev/lukebemish/codecextras/structured/KeyStoringInterpreter.java
+++ b/src/main/java/dev/lukebemish/codecextras/structured/KeyStoringInterpreter.java
@@ -22,7 +22,7 @@ public <A> DataResult<App<Mu, A>> keyed(Key<A> key) {
     public <MuO extends K1, MuP extends K1, T> DataResult<App<Mu, App<MuO, T>>> parametricallyKeyed(Key2<MuP, MuO> key, App<MuP, T> parameter) {
         return parametricKeys.get(key)
             .map(ParametricKeyedValue::unbox)
-            .map(val -> val.converter().convert(parameter))
+            .map(val -> val.convert(parameter))
             .map(DataResult::success)
             .orElse(DataResult.error(() -> "Unknown key "+key.name()));
     }
diff --git a/src/main/java/dev/lukebemish/codecextras/structured/MapCodecInterpreter.java b/src/main/java/dev/lukebemish/codecextras/structured/MapCodecInterpreter.java
index 5d5da66..e567d48 100644
--- a/src/main/java/dev/lukebemish/codecextras/structured/MapCodecInterpreter.java
+++ b/src/main/java/dev/lukebemish/codecextras/structured/MapCodecInterpreter.java
@@ -29,13 +29,13 @@ public <B> App<CodecInterpreter.Holder.Mu, B> convert(App<Holder.Mu, B> app) {
             @Override
             public <A extends K1, B extends K1> App2<ParametricKeyedValue.Mu<CodecInterpreter.Holder.Mu>, A, B> convert(App2<ParametricKeyedValue.Mu<Holder.Mu>, A, B> input) {
                 var unboxed = ParametricKeyedValue.unbox(input);
-                return new ParametricKeyedValue<>(new ParametricKeyedValue.Converter<>() {
-					@Override
-					public <T> App<CodecInterpreter.Holder.Mu, App<B, T>> convert(App<A, T> parameter) {
-						var mapCodec = unbox(unboxed.converter().convert(parameter));
-						return new CodecInterpreter.Holder<>(mapCodec.codec());
-					}
-				});
+                return new ParametricKeyedValue<>() {
+                    @Override
+                    public <T> App<CodecInterpreter.Holder.Mu, App<B, T>> convert(App<A, T> parameter) {
+                        var mapCodec = unbox(unboxed.convert(parameter));
+                        return new CodecInterpreter.Holder<>(mapCodec.codec());
+                    }
+                };
             }
         }).join(parametricCodecKeys));
     }
diff --git a/src/main/java/dev/lukebemish/codecextras/structured/ParametricKeyedValue.java b/src/main/java/dev/lukebemish/codecextras/structured/ParametricKeyedValue.java
index c20e18c..0bdc345 100644
--- a/src/main/java/dev/lukebemish/codecextras/structured/ParametricKeyedValue.java
+++ b/src/main/java/dev/lukebemish/codecextras/structured/ParametricKeyedValue.java
@@ -5,14 +5,12 @@
 import com.mojang.datafixers.kinds.K1;
 import com.mojang.datafixers.kinds.K2;
 
-public record ParametricKeyedValue<N extends K1, MuP extends K1, MuO extends K1>(Converter<N, MuP, MuO> converter) implements App2<ParametricKeyedValue.Mu<N>, MuP, MuO> {
-    public static class Mu<N extends K1> implements K2 {}
+public interface ParametricKeyedValue<N extends K1, MuP extends K1, MuO extends K1> extends App2<ParametricKeyedValue.Mu<N>, MuP, MuO> {
+    class Mu<N extends K1> implements K2 {}
 
-    public interface Converter<N extends K1, MuP extends K1, MuO extends K1> {
-        <T> App<N, App<MuO, T>> convert(App<MuP, T> parameter);
-    }
+    <T> App<N, App<MuO, T>> convert(App<MuP, T> parameter);
 
-    public static <N extends K1, MuP extends K1, MuO extends K1> ParametricKeyedValue<N, MuP, MuO> unbox(App2<Mu<N>, MuP, MuO> boxed) {
+    static <N extends K1, MuP extends K1, MuO extends K1> ParametricKeyedValue<N, MuP, MuO> unbox(App2<Mu<N>, MuP, MuO> boxed) {
         return (ParametricKeyedValue<N, MuP, MuO>) boxed;
     }
 }
diff --git a/src/test/java/dev/lukebemish/codecextras/test/structured/TestParametricKeys.java b/src/test/java/dev/lukebemish/codecextras/test/structured/TestParametricKeys.java
index 65d9ad8..8eaa8fa 100644
--- a/src/test/java/dev/lukebemish/codecextras/test/structured/TestParametricKeys.java
+++ b/src/test/java/dev/lukebemish/codecextras/test/structured/TestParametricKeys.java
@@ -52,12 +52,12 @@ private static <T> Codec<WithType<T>> withTypeCodec(Prefix<T> prefix) {
     private static final Codec<WithType<Integer>> CODEC = new CodecInterpreter(
         Keys.<CodecInterpreter.Holder.Mu, Object>builder().build(),
         Keys2.<ParametricKeyedValue.Mu<CodecInterpreter.Holder.Mu>, K1, K1>builder()
-            .add(WITH_TYPE, new ParametricKeyedValue<>(new ParametricKeyedValue.Converter<>() {
+            .add(WITH_TYPE, new ParametricKeyedValue<>() {
                 @Override
                 public <T> App<CodecInterpreter.Holder.Mu, App<WithType.Mu, T>> convert(App<Prefix.Mu, T> parameter) {
                     return new CodecInterpreter.Holder<>(withTypeCodec(Prefix.unbox(parameter)).xmap(Function.identity(), WithType::unbox));
                 }
-            }))
+            })
             .build()
     ).interpret(STRUCTURE).getOrThrow();