diff --git a/api-reports/2_12.txt b/api-reports/2_12.txt
index f03765312..a96232668 100644
--- a/api-reports/2_12.txt
+++ b/api-reports/2_12.txt
@@ -25109,7 +25109,7 @@ StereoPannerNode[JT] def removeEventListener[T <: Event](`type`: String, listene
 Storage[JC] def clear(): Unit
 Storage[JC] def getItem(key: String): String
 Storage[JC] def key(index: Int): String
-Storage[JC] var length: Int
+Storage[JC] def length: Int
 Storage[JC] def removeItem(key: String): Unit
 Storage[JC] def setItem(key: String, data: String): Unit
 StorageEstimate[JT] val quota: Double
diff --git a/api-reports/2_13.txt b/api-reports/2_13.txt
index f03765312..a96232668 100644
--- a/api-reports/2_13.txt
+++ b/api-reports/2_13.txt
@@ -25109,7 +25109,7 @@ StereoPannerNode[JT] def removeEventListener[T <: Event](`type`: String, listene
 Storage[JC] def clear(): Unit
 Storage[JC] def getItem(key: String): String
 Storage[JC] def key(index: Int): String
-Storage[JC] var length: Int
+Storage[JC] def length: Int
 Storage[JC] def removeItem(key: String): Unit
 Storage[JC] def setItem(key: String, data: String): Unit
 StorageEstimate[JT] val quota: Double
diff --git a/dom/src/main/scala/org/scalajs/dom/Storage.scala b/dom/src/main/scala/org/scalajs/dom/Storage.scala
index ad505cc7d..c86339cb2 100644
--- a/dom/src/main/scala/org/scalajs/dom/Storage.scala
+++ b/dom/src/main/scala/org/scalajs/dom/Storage.scala
@@ -16,7 +16,7 @@ import scala.scalajs.js.annotation._
 @js.native
 @JSGlobal
 class Storage extends js.Object {
-  var length: Int = js.native
+  def length: Int = js.native
 
   def getItem(key: String): String = js.native