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 1186b2c606f632..de5bc44f1ba793 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
@@ -12,6 +12,7 @@
     <Nullable>enable</Nullable>
     <IsOSXLike Condition="'$(TargetsOSX)' == 'true' or '$(TargetsMacCatalyst)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</IsOSXLike>
     <IsiOSLike Condition="'$(TargetsMacCatalyst)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'">true</IsiOSLike>
+    <IsMobileLike Condition="'$(TargetsBrowser)' == 'true' or '$(IsiOSLike)' == 'true' or '$(TargetsAndroid)' == 'true'">true</IsMobileLike>
     <SupportsArmIntrinsics Condition="'$(Platform)' == 'arm64'">true</SupportsArmIntrinsics>
     <SupportsX86Intrinsics Condition="'$(Platform)' == 'x64' or ('$(Platform)' == 'x86' and '$(TargetsUnix)' != 'true')">true</SupportsX86Intrinsics>
     <ILLinkSharedDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkSharedDirectory>
@@ -856,7 +857,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Intrinsics\Vector64_1.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Intrinsics\Vector64DebugView_1.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Intrinsics\X86\Enums.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Loader\AssemblyDependencyResolver.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Loader\AssemblyLoadContext.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Loader\LibraryNameVariation.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\MemoryFailPoint.cs" />
@@ -1222,6 +1222,15 @@
       <Link>Common\System\Threading\Tasks\TaskToApm.cs</Link>
     </Compile>
   </ItemGroup>
+  <ItemGroup Condition="'$(IsMobileLike)' != 'true'">
+    <Compile Include="$(CommonPath)Interop\Interop.HostPolicy.cs">
+      <Link>Common\Interop\Interop.HostPolicy.cs</Link>
+    </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Loader\AssemblyDependencyResolver.cs" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(IsMobileLike)' == 'true'">
+    <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\Loader\AssemblyDependencyResolver.PlatformNotSupported.cs" />
+  </ItemGroup>
   <ItemGroup>
     <Compile Include="$(CommonPath)Interop\Windows\Advapi32\Interop.ActivityControl.cs">
       <Link>Common\Interop\Windows\Advapi32\Interop.ActivityControl.cs</Link>
@@ -1232,9 +1241,6 @@
     <Compile Include="$(CommonPath)Interop\Windows\Advapi32\Interop.EVENT_INFO_CLASS.cs">
       <Link>Common\Interop\Windows\Advapi32\Interop.EVENT_INFO_CLASS.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)Interop\Interop.HostPolicy.cs">
-      <Link>Common\Interop\Interop.HostPolicy.cs</Link>
-    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Tracing\ActivityTracker.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Tracing\DiagnosticCounter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Diagnostics\Tracing\CounterGroup.cs" />
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.PlatformNotSupported.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.PlatformNotSupported.cs
new file mode 100644
index 00000000000000..06df366a1c73df
--- /dev/null
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.PlatformNotSupported.cs
@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Reflection;
+using System.Runtime.Versioning;
+
+namespace System.Runtime.Loader
+{
+    [UnsupportedOSPlatform("android")]
+    [UnsupportedOSPlatform("browser")]
+    [UnsupportedOSPlatform("ios")]
+    [UnsupportedOSPlatform("maccatalyst")]
+    [UnsupportedOSPlatform("tvos")]
+    public sealed class AssemblyDependencyResolver
+    {
+        public AssemblyDependencyResolver(string componentAssemblyPath)
+        {
+            throw new PlatformNotSupportedException();
+        }
+
+        public string? ResolveAssemblyToPath(AssemblyName assemblyName)
+        {
+            throw new PlatformNotSupportedException();
+        }
+
+        public string? ResolveUnmanagedDllToPath(string unmanagedDllName)
+        {
+            throw new PlatformNotSupportedException();
+        }
+    }
+}
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.cs
index 644e536757b1b4..e2c1862767502b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/Loader/AssemblyDependencyResolver.cs
@@ -5,10 +5,16 @@
 using System.IO;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
 using System.Text;
 
 namespace System.Runtime.Loader
 {
+    [UnsupportedOSPlatform("android")]
+    [UnsupportedOSPlatform("browser")]
+    [UnsupportedOSPlatform("ios")]
+    [UnsupportedOSPlatform("maccatalyst")]
+    [UnsupportedOSPlatform("tvos")]
     public sealed class AssemblyDependencyResolver
     {
         /// <summary>
diff --git a/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.cs b/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.cs
index e42a0642b32ea9..3aaa591f624114 100644
--- a/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.cs
+++ b/src/libraries/System.Runtime.Loader/ref/System.Runtime.Loader.cs
@@ -22,6 +22,11 @@ public MetadataUpdateHandlerAttribute([System.Diagnostics.CodeAnalysis.Dynamical
 }
 namespace System.Runtime.Loader
 {
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("android")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("browser")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("ios")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("maccatalyst")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("tvos")]
     public sealed partial class AssemblyDependencyResolver
     {
         public AssemblyDependencyResolver(string componentAssemblyPath) { }