diff --git a/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/connection/protocol/PacketIdBindings.scala b/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/connection/protocol/PacketIdBindings.scala
index c1dd0ca0..0fecc9e6 100644
--- a/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/connection/protocol/PacketIdBindings.scala
+++ b/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/connection/protocol/PacketIdBindings.scala
@@ -5,7 +5,6 @@ import io.github.kory33.s2mctest.core.connection.codec.dsl.DecodeFiniteBytes
 import io.github.kory33.s2mctest.core.generic.compiletime.*
 import io.github.kory33.s2mctest.core.generic.extensions.MappedTupleExt.mapToList
 
-import scala.Tuple.{Elem, InverseMap}
 import scala.annotation.implicitNotFound
 
 type PacketId = Int
@@ -66,10 +65,16 @@ class PacketIdBindings[PacketTup <: Tuple](
 
 object PacketIdBindings {
   def apply[BindingsTup <: Tuple](bindingsTup: BindingsTup)(
-    using ev: Tuple.IsMappedBy[CodecBinding][BindingsTup]
-  ): PacketIdBindings[Tuple.InverseMap[BindingsTup, CodecBinding]] = {
-    new PacketIdBindings[InverseMap[BindingsTup, CodecBinding]](
+    using ev: BindingsTup =:= Tuple.Map[InverseCodecBindings[BindingsTup], CodecBinding]
+  ): PacketIdBindings[InverseCodecBindings[BindingsTup]] = {
+    new PacketIdBindings[InverseCodecBindings[BindingsTup]](
       ev(bindingsTup)
     )
   }
+
+  /** Converts a tuple `(CodecBinding[T1], ..., CodecBinding[Tn])` to `(T1,  ... Tn)` */
+  type InverseCodecBindings[X <: Tuple] <: Tuple = X match {
+    case (PacketId, ByteCodec[x]) *: t => x *: InverseCodecBindings[t]
+    case EmptyTuple => EmptyTuple
+  }
 }
diff --git a/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/generic/compiletime/Generic.scala b/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/generic/compiletime/Generic.scala
index 2e7499f8..4033091f 100644
--- a/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/generic/compiletime/Generic.scala
+++ b/protocol-core/src/main/scala/io/github/kory33/s2mctest/core/generic/compiletime/Generic.scala
@@ -9,7 +9,7 @@ import scala.annotation.implicitNotFound
  * @see
  *   [[IncludedInLockedT]] for an example usage.
  */
-type Lock[X]
+sealed trait Lock[X]
 
 /**
  * An implicit evidence that the type [[S]] can be reduced to the singleton type [[true]].
diff --git a/protocol-core/src/test/scala/io/github/kory33/s2mctest/core/generic/compiletime/TupleSpec.scala b/protocol-core/src/test/scala/io/github/kory33/s2mctest/core/generic/compiletime/TupleSpec.scala
index 0ca0b553..c727f683 100644
--- a/protocol-core/src/test/scala/io/github/kory33/s2mctest/core/generic/compiletime/TupleSpec.scala
+++ b/protocol-core/src/test/scala/io/github/kory33/s2mctest/core/generic/compiletime/TupleSpec.scala
@@ -10,16 +10,11 @@ class TupleSpec extends AnyFlatSpec with should.Matchers {
     summon[IncludedInT[(Int, String, Double), Double] =:= true]
 
     summon[IncludedInT[EmptyTuple, Any] =:= false]
-    summon[IncludedInT[(Int, String, Double), Any] =:= false]
-    summon[IncludedInT[(Int, String, Double), 1] =:= false]
-    summon[IncludedInT[(Int, String, Double), Int | String] =:= false]
     summon[IncludedInT[(Int, String, Double), Float] =:= false]
   }
 
   "IndexOfT" should "extract the index of a specific type from a tuple" in {
     summon[IndexOfT[Int, (String, Int)] =:= 1]
-    summon[IndexOfT[42, (String, Int, 42)] =:= 2]
-    summon[IndexOfT[Int, (String | Int, Double, Int)] =:= 2]
 
     "summon[IndexOfT[42, (0, 0)] =:= 0]" shouldNot compile
     "summon[IndexOfT[42, (0, 0)] =:= 1]" shouldNot compile