diff --git a/apispec-model/src/main/scala/sttp/apispec/validation/SchemaComparator.scala b/apispec-model/src/main/scala/sttp/apispec/validation/SchemaComparator.scala
index 9555c79..6b90516 100644
--- a/apispec-model/src/main/scala/sttp/apispec/validation/SchemaComparator.scala
+++ b/apispec-model/src/main/scala/sttp/apispec/validation/SchemaComparator.scala
@@ -52,6 +52,7 @@ private class SchemaComparator(
       case s@LocalReference(name) =>
         def noSchema: Nothing =
           throw new NoSuchElementException(s"could not resolve schema reference ${s.$ref.get}")
+
         normalize(named.getOrElse(name, noSchema), named)
       case s => s
     }
@@ -198,7 +199,7 @@ private class SchemaComparator(
       types.nonEmpty && !types.contains(SchemaType.Array) && !types.contains(SchemaType.Object)
     } && s == Schema( // check if the schema contains only primitive type assertions
       `type` = s.`type`,
-      enum = s.`enum`,
+      `enum` = s.`enum`,
       const = s.`const`,
       format = s.format,
 
@@ -275,7 +276,7 @@ private class SchemaComparator(
 
   private def discriminatorMapping(schema: Schema): Option[ListMap[String, SchemaLike]] =
     schema.discriminator.map { disc =>
-      val baseMapping = schema.oneOf.collect({ case s@LocalReference(name) => name -> s }).to(ListMap)
+      val baseMapping = ListMap(schema.oneOf.collect({ case s@LocalReference(name) => name -> s }): _*)
       baseMapping ++ disc.mapping.getOrElse(ListMap.empty).map {
         case (name, ref) => name -> Schema($ref = Some(ref))
       }
diff --git a/apispec-model/src/main/scala/sttp/apispec/validation/SchemaCompatibilityIssue.scala b/apispec-model/src/main/scala/sttp/apispec/validation/SchemaCompatibilityIssue.scala
index bb0118e..efe0cac 100644
--- a/apispec-model/src/main/scala/sttp/apispec/validation/SchemaCompatibilityIssue.scala
+++ b/apispec-model/src/main/scala/sttp/apispec/validation/SchemaCompatibilityIssue.scala
@@ -8,7 +8,7 @@ sealed abstract class SchemaCompatibilityIssue extends Product {
   override def toString: String = s"$productPrefix($description)"
 
   protected def pluralize(what: String, coll: Seq[Any]): String =
-    if (coll.sizeIs == 1) s"$what ${coll.head}"
+    if (coll.lengthCompare(1) == 0) s"$what ${coll.head}"
     else s"${what}s ${coll.mkString(", ")}"
 
   protected def form(coll: Seq[Any], singular: String, plural: String): String =