diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index df99a3ffcec74..ce942ea7e8569 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -2157,14 +2157,15 @@
Link="Common\Interop\Linux\Interop.ProcFsStat.TryReadStatusFile.cs" />
-
-
+
+
diff --git a/src/libraries/System.Private.CoreLib/src/System/Environment.iOS.cs b/src/libraries/System.Private.CoreLib/src/System/Environment.iOS.cs
new file mode 100644
index 0000000000000..90512ca598bd8
--- /dev/null
+++ b/src/libraries/System.Private.CoreLib/src/System/Environment.iOS.cs
@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.InteropServices;
+
+namespace System
+{
+ public static partial class Environment
+ {
+ // iOS/tvOS aren't allowed to call libproc APIs so return 0 here, this also matches what we returned in earlier releases
+ public static long WorkingSet => 0;
+ }
+}
diff --git a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
index 415cafb9f02c2..5d2bf2785491f 100644
--- a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
+++ b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
@@ -236,7 +236,7 @@ public void Version_Valid()
[Fact]
public void WorkingSet_Valid()
{
- if (PlatformDetection.IsBrowser)
+ if (PlatformDetection.IsBrowser || PlatformDetection.IsiOS || PlatformDetection.IstvOS)
Assert.Equal(0, Environment.WorkingSet);
else
Assert.True(Environment.WorkingSet > 0, "Expected positive WorkingSet value");