diff --git a/core/src/main/scala-3/caliban/schema/SchemaDerivation.scala b/core/src/main/scala-3/caliban/schema/SchemaDerivation.scala
index d21f578ca5..47b14939a1 100644
--- a/core/src/main/scala-3/caliban/schema/SchemaDerivation.scala
+++ b/core/src/main/scala-3/caliban/schema/SchemaDerivation.scala
@@ -99,12 +99,12 @@ trait CommonSchemaDerivation {
 
     private lazy val members = _members.toVector // Vector's .apply is O(1) vs List's O(N)
 
-    private lazy val subTypes = members.map { case (label, subTypeAnnotations, schema) =>
+    private lazy val subTypes = members.map { (label, subTypeAnnotations, schema) =>
       (label, schema.toType_(), subTypeAnnotations)
-    }.sortBy { case (label, _, _) => label }.toList
+    }.sortBy(_._1).toList
 
     private lazy val isEnum = subTypes.forall { (_, t, _) =>
-      t.allFields.isEmpty && t.allInputFields.isEmpty
+      unpackLeafTypes(t).foldLeft(true)((acc, t) => acc && t.allFields.isEmpty && t.allInputFields.isEmpty)
     }
 
     private lazy val isInterface = annotations.exists {
@@ -259,7 +259,7 @@ trait CommonSchemaDerivation {
       getDescription(annotations),
       subTypes.collect { case (name, __Type(_, _, description, _, _, _, _, _, _, _, _, _), annotations) =>
         __EnumValue(
-          name,
+          getName(annotations, name),
           description,
           getDeprecatedReason(annotations).isDefined,
           getDeprecatedReason(annotations),
diff --git a/core/src/test/scala/caliban/schema/SchemaDerivationIssuesSpec.scala b/core/src/test/scala/caliban/schema/SchemaDerivationIssuesSpec.scala
index 07d7cc3356..e5c7643534 100644
--- a/core/src/test/scala/caliban/schema/SchemaDerivationIssuesSpec.scala
+++ b/core/src/test/scala/caliban/schema/SchemaDerivationIssuesSpec.scala
@@ -1,6 +1,6 @@
 package caliban.schema
 
-import caliban.schema.Annotations.{ GQLDescription, GQLInterface, GQLUnion }
+import caliban.schema.Annotations.{ GQLDescription, GQLInterface, GQLName, GQLUnion }
 import zio.Chunk
 import zio.test.ZIOSpecDefault
 import zio.test._
@@ -101,6 +101,45 @@ object SchemaDerivationIssuesSpec extends ZIOSpecDefault {
             |  param: MyInterface!
             |}""".stripMargin
       )
+    },
+    test("i1989") {
+      import i1989._
+
+      assertTrue(
+        schema ==
+          """schema {
+            |  query: Queries
+            |}
+            |
+            |union Level1 = Level3
+            |
+            |type Level3 {
+            |  value: Boolean!
+            |}
+            |
+            |type Queries {
+            |  level: Level1!
+            |}""".stripMargin
+      )
+    },
+    test("i1990") {
+      import i1990._
+
+      assertTrue(
+        schema ==
+          """schema {
+            |  query: Queries
+            |}
+            |
+            |enum PrefixOperator {
+            |  PrefixOperatorGreaterThan
+            |  PrefixOperatorLessThan
+            |}
+            |
+            |type Queries {
+            |  op: PrefixOperator!
+            |}""".stripMargin
+      )
     }
   )
 }
@@ -200,3 +239,59 @@ private object i1977 {
     graphQL(RootResolver(queries))
   }.render
 }
+
+private object i1989 {
+  sealed trait Level1
+  object Level1 {
+    implicit val schema: Schema[Any, Level1] = Schema.gen
+
+    sealed trait Level2 extends Level1
+    object Level2 {
+      implicit val schema: Schema[Any, Level2] = Schema.gen
+
+      case class Level3(value: Boolean) extends Level2
+      object Level3 {
+        implicit val schema: Schema[Any, Level3] = Schema.gen
+      }
+    }
+  }
+
+  case class Queries(level: Level1)
+  object Queries {
+    implicit val schema: Schema[Any, Queries] = Schema.gen
+  }
+
+  val schema = {
+    val queries = Queries(level = Level1.Level2.Level3(false))
+    caliban.graphQL(RootResolver(queries))
+  }.render
+}
+
+object i1990 {
+  @GQLName("PrefixOperator")
+  sealed trait Operator
+  object Operator {
+    @GQLName("PrefixOperatorGreaterThan")
+    case object GreaterThan extends Operator {
+      implicit val schema: Schema[Any, GreaterThan.type] = Schema.gen
+    }
+
+    @GQLName("PrefixOperatorLessThan")
+    case object LessThan extends Operator {
+      implicit val schema: Schema[Any, LessThan.type] = Schema.gen
+    }
+
+    implicit val schema: Schema[Any, Operator] = Schema.gen
+  }
+
+  case class Queries(op: Operator)
+
+  object Queries {
+    implicit val schema: Schema[Any, Queries] = Schema.gen
+  }
+
+  val schema = {
+    val queries = Queries(op = Operator.LessThan)
+    caliban.graphQL(RootResolver(queries))
+  }.render
+}