diff --git a/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netcoreapp.cs b/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netcoreapp.cs
index c606bf0a9c..d2f9cec907 100644
--- a/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netcoreapp.cs
+++ b/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netcoreapp.cs
@@ -28,8 +28,6 @@ namespace Microsoft.Extensions.Localization
     }
     public partial class ResourceManagerStringLocalizer : Microsoft.Extensions.Localization.IStringLocalizer
     {
-        public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, Microsoft.Extensions.Localization.Internal.AssemblyWrapper resourceAssemblyWrapper, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
-        public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, Microsoft.Extensions.Localization.Internal.IResourceStringProvider resourceStringProvider, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
         public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, System.Reflection.Assembly resourceAssembly, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
         public virtual Microsoft.Extensions.Localization.LocalizedString this[string name] { get { throw null; } }
         public virtual Microsoft.Extensions.Localization.LocalizedString this[string name, params object[] arguments] { get { throw null; } }
@@ -62,22 +60,3 @@ namespace Microsoft.Extensions.Localization
         public string RootNamespace { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
     }
 }
-namespace Microsoft.Extensions.Localization.Internal
-{
-    public partial class AssemblyWrapper
-    {
-        public AssemblyWrapper(System.Reflection.Assembly assembly) { }
-        public System.Reflection.Assembly Assembly { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public virtual string FullName { get { throw null; } }
-        public virtual System.IO.Stream? GetManifestResourceStream(string name) { throw null; }
-    }
-    public partial interface IResourceStringProvider
-    {
-        System.Collections.Generic.IList<string>? GetAllResourceStrings(System.Globalization.CultureInfo culture, bool throwOnMissing);
-    }
-    public partial class ResourceManagerStringProvider : Microsoft.Extensions.Localization.Internal.IResourceStringProvider
-    {
-        public ResourceManagerStringProvider(Microsoft.Extensions.Localization.IResourceNamesCache resourceCache, System.Resources.ResourceManager resourceManager, System.Reflection.Assembly assembly, string baseName) { }
-        public System.Collections.Generic.IList<string>? GetAllResourceStrings(System.Globalization.CultureInfo culture, bool throwOnMissing) { throw null; }
-    }
-}
diff --git a/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netstandard2.0.cs b/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netstandard2.0.cs
index c606bf0a9c..d2f9cec907 100644
--- a/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netstandard2.0.cs
+++ b/src/Localization/Localization/ref/Microsoft.Extensions.Localization.netstandard2.0.cs
@@ -28,8 +28,6 @@ namespace Microsoft.Extensions.Localization
     }
     public partial class ResourceManagerStringLocalizer : Microsoft.Extensions.Localization.IStringLocalizer
     {
-        public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, Microsoft.Extensions.Localization.Internal.AssemblyWrapper resourceAssemblyWrapper, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
-        public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, Microsoft.Extensions.Localization.Internal.IResourceStringProvider resourceStringProvider, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
         public ResourceManagerStringLocalizer(System.Resources.ResourceManager resourceManager, System.Reflection.Assembly resourceAssembly, string baseName, Microsoft.Extensions.Localization.IResourceNamesCache resourceNamesCache, Microsoft.Extensions.Logging.ILogger logger) { }
         public virtual Microsoft.Extensions.Localization.LocalizedString this[string name] { get { throw null; } }
         public virtual Microsoft.Extensions.Localization.LocalizedString this[string name, params object[] arguments] { get { throw null; } }
@@ -62,22 +60,3 @@ namespace Microsoft.Extensions.Localization
         public string RootNamespace { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
     }
 }
-namespace Microsoft.Extensions.Localization.Internal
-{
-    public partial class AssemblyWrapper
-    {
-        public AssemblyWrapper(System.Reflection.Assembly assembly) { }
-        public System.Reflection.Assembly Assembly { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public virtual string FullName { get { throw null; } }
-        public virtual System.IO.Stream? GetManifestResourceStream(string name) { throw null; }
-    }
-    public partial interface IResourceStringProvider
-    {
-        System.Collections.Generic.IList<string>? GetAllResourceStrings(System.Globalization.CultureInfo culture, bool throwOnMissing);
-    }
-    public partial class ResourceManagerStringProvider : Microsoft.Extensions.Localization.Internal.IResourceStringProvider
-    {
-        public ResourceManagerStringProvider(Microsoft.Extensions.Localization.IResourceNamesCache resourceCache, System.Resources.ResourceManager resourceManager, System.Reflection.Assembly assembly, string baseName) { }
-        public System.Collections.Generic.IList<string>? GetAllResourceStrings(System.Globalization.CultureInfo culture, bool throwOnMissing) { throw null; }
-    }
-}
diff --git a/src/Localization/Localization/src/Internal/AssemblyWrapper.cs b/src/Localization/Localization/src/Internal/AssemblyWrapper.cs
index 813d8717b1..0cb34fc7a5 100644
--- a/src/Localization/Localization/src/Internal/AssemblyWrapper.cs
+++ b/src/Localization/Localization/src/Internal/AssemblyWrapper.cs
@@ -5,13 +5,13 @@ using System;
 using System.IO;
 using System.Reflection;
 
-namespace Microsoft.Extensions.Localization.Internal
+namespace Microsoft.Extensions.Localization
 {
     /// <summary>
     /// This API supports infrastructure and is not intended to be used
     /// directly from your code. This API may change or be removed in future releases.
     /// </summary>
-    public class AssemblyWrapper
+    internal class AssemblyWrapper
     {
         public AssemblyWrapper(Assembly assembly)
         {
diff --git a/src/Localization/Localization/src/Internal/IResourceStringProvider.cs b/src/Localization/Localization/src/Internal/IResourceStringProvider.cs
index 16df0065ac..b70264e7eb 100644
--- a/src/Localization/Localization/src/Internal/IResourceStringProvider.cs
+++ b/src/Localization/Localization/src/Internal/IResourceStringProvider.cs
@@ -4,13 +4,13 @@
 using System.Collections.Generic;
 using System.Globalization;
 
-namespace Microsoft.Extensions.Localization.Internal
+namespace Microsoft.Extensions.Localization
 {
     /// <summary>
     /// This API supports infrastructure and is not intended to be used
     /// directly from your code. This API may change or be removed in future releases.
     /// </summary>
-    public interface IResourceStringProvider
+    internal interface IResourceStringProvider
     {
         IList<string>? GetAllResourceStrings(CultureInfo culture, bool throwOnMissing);
     }
diff --git a/src/Localization/Localization/src/Internal/ResourceManagerStringProvider.cs b/src/Localization/Localization/src/Internal/ResourceManagerStringProvider.cs
index 00850b1655..5955ae5032 100644
--- a/src/Localization/Localization/src/Internal/ResourceManagerStringProvider.cs
+++ b/src/Localization/Localization/src/Internal/ResourceManagerStringProvider.cs
@@ -7,13 +7,13 @@ using System.Globalization;
 using System.Reflection;
 using System.Resources;
 
-namespace Microsoft.Extensions.Localization.Internal
+namespace Microsoft.Extensions.Localization
 {
     /// <summary>
     /// This API supports infrastructure and is not intended to be used
     /// directly from your code. This API may change or be removed in future releases.
     /// </summary>
-    public class ResourceManagerStringProvider : IResourceStringProvider
+    internal class ResourceManagerStringProvider : IResourceStringProvider
     {
         private readonly IResourceNamesCache _resourceNamesCache;
         private readonly ResourceManager _resourceManager;
diff --git a/src/Localization/Localization/src/ResourceManagerStringLocalizer.cs b/src/Localization/Localization/src/ResourceManagerStringLocalizer.cs
index b1e9845a0c..c18a75bddd 100644
--- a/src/Localization/Localization/src/ResourceManagerStringLocalizer.cs
+++ b/src/Localization/Localization/src/ResourceManagerStringLocalizer.cs
@@ -53,11 +53,9 @@ namespace Microsoft.Extensions.Localization
         /// <summary>
         /// Intended for testing purposes only.
         /// </summary>
-        public ResourceManagerStringLocalizer(
+        internal ResourceManagerStringLocalizer(
             ResourceManager resourceManager,
-#pragma warning disable PUB0001 // Pubternal type AssemblyWrapper in public API
             AssemblyWrapper resourceAssemblyWrapper,
-#pragma warning restore PUB0001 // Pubternal type AssemblyWrapper in public API
             string baseName,
             IResourceNamesCache resourceNamesCache,
             ILogger logger)
@@ -77,11 +75,9 @@ namespace Microsoft.Extensions.Localization
         /// <summary>
         /// Intended for testing purposes only.
         /// </summary>
-        public ResourceManagerStringLocalizer(
+        internal ResourceManagerStringLocalizer(
             ResourceManager resourceManager,
-#pragma warning disable PUB0001 // Pubternal type IResourceStringProvider in public API
             IResourceStringProvider resourceStringProvider,
-#pragma warning restore PUB0001 // Pubternal type IResourceStringProvider in public API
             string baseName,
             IResourceNamesCache resourceNamesCache,
             ILogger logger)
@@ -180,7 +176,7 @@ namespace Microsoft.Extensions.Localization
         }
 
         /// <summary>
-        /// Gets a resource string from the <see cref="_resourceManager"/> and returns <c>null</c> instead of
+        /// Gets a resource string from a <see cref="ResourceManager"/> and returns <c>null</c> instead of
         /// throwing exceptions if a match isn't found.
         /// </summary>
         /// <param name="name">The name of the string resource.</param>
diff --git a/src/Localization/Localization/test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerTest.cs b/src/Localization/Localization/test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerTest.cs
index a2bd1ed7c1..837d12274d 100644
--- a/src/Localization/Localization/test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerTest.cs
+++ b/src/Localization/Localization/test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerTest.cs
@@ -239,7 +239,7 @@ namespace Microsoft.Extensions.Localization
 
         private ILogger Logger => new TestLoggerFactory(Sink, enabled: true).CreateLogger<ResourceManagerStringLocalizer>();
 
-        public class TestResourceManager : ResourceManager
+        internal class TestResourceManager : ResourceManager
         {
             private AssemblyWrapper _assemblyWrapper;
 
@@ -259,7 +259,7 @@ namespace Microsoft.Extensions.Localization
             }
         }
 
-        public class TestResourceStringProvider : ResourceManagerStringProvider
+        internal class TestResourceStringProvider : ResourceManagerStringProvider
         {
             public TestResourceStringProvider(
                     IResourceNamesCache resourceCache,
@@ -271,7 +271,7 @@ namespace Microsoft.Extensions.Localization
             }
         }
 
-        public class TestAssemblyWrapper : AssemblyWrapper
+        internal class TestAssemblyWrapper : AssemblyWrapper
         {
             public TestAssemblyWrapper()
                 : this(typeof(TestAssemblyWrapper))