diff --git a/compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala b/compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala
index 8d811e20..a5511615 100644
--- a/compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala
+++ b/compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala
@@ -360,7 +360,7 @@ private[compat] trait PackageShared {
     new RandomExtensions(self)
 }
 
-class ArrayExtensions(private val fact: Array.type) extends AnyVal {
+final class ArrayExtensions(private val fact: Array.type) extends AnyVal {
   def from[A: ClassTag](source: TraversableOnce[A]): Array[A] =
     source match {
       case it: Iterable[A] => it.toArray[A]