diff --git a/src/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs b/src/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs
index 8ecf8e715762..f24bbefe459d 100644
--- a/src/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs
+++ b/src/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs
@@ -84,7 +84,7 @@ public AttributeProviderAttribute(System.Type type) { }
     }
     public abstract partial class BaseNumberConverter : System.ComponentModel.TypeConverter
     {
-        protected BaseNumberConverter() { }
+        internal BaseNumberConverter() { }
         public override bool CanConvertFrom(System.ComponentModel.ITypeDescriptorContext context, System.Type sourceType) { throw null; }
         public override bool CanConvertTo(System.ComponentModel.ITypeDescriptorContext context, System.Type destinationType) { throw null; }
         public override object ConvertFrom(System.ComponentModel.ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value) { throw null; }
diff --git a/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs b/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs
index b631cde30d84..840378ab0750 100644
--- a/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs
+++ b/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs
@@ -11,6 +11,8 @@ namespace System.ComponentModel
     /// </summary>
     public abstract class BaseNumberConverter : TypeConverter
     {
+        internal BaseNumberConverter() { }
+
         /// <summary>
         /// Determines whether this editor will attempt to convert hex (0x or #) strings
         /// </summary>
diff --git a/src/shims/ApiCompatBaseline.netcoreapp.netstandard.txt b/src/shims/ApiCompatBaseline.netcoreapp.netstandard.txt
index f9326ee8077a..9b33da3ea6e7 100644
--- a/src/shims/ApiCompatBaseline.netcoreapp.netstandard.txt
+++ b/src/shims/ApiCompatBaseline.netcoreapp.netstandard.txt
@@ -26,4 +26,11 @@ Compat issues with assembly System.Security.Cryptography.Pkcs:
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.Certificates.set(System.Security.Cryptography.X509Certificates.X509Certificate2Collection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.SignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.UnsignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 21
+Compat issues with assembly System.ComponentModel.TypeConverter:
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 27
diff --git a/src/shims/ApiCompatBaseline.netcoreapp.netstandardOnly.txt b/src/shims/ApiCompatBaseline.netcoreapp.netstandardOnly.txt
index b038da471ac3..a5f2a50cd687 100644
--- a/src/shims/ApiCompatBaseline.netcoreapp.netstandardOnly.txt
+++ b/src/shims/ApiCompatBaseline.netcoreapp.netstandardOnly.txt
@@ -79,4 +79,10 @@ MembersMustExist : Member 'System.String.Chars.get(System.Range)' does not exist
 MembersMustExist : Member 'System.String.Substring(System.Index)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.String.Substring(System.Range)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Utf8String.Slice(System.Int32, System.Int32)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 80
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 86
diff --git a/src/shims/ApiCompatBaseline.uap.netstandard.txt b/src/shims/ApiCompatBaseline.uap.netstandard.txt
index 9478e274be96..2dc0f4c796a8 100644
--- a/src/shims/ApiCompatBaseline.uap.netstandard.txt
+++ b/src/shims/ApiCompatBaseline.uap.netstandard.txt
@@ -99,4 +99,11 @@ Compat issues with assembly System.Security.Cryptography.Pkcs:
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.Certificates.set(System.Security.Cryptography.X509Certificates.X509Certificate2Collection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.SignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.UnsignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 86
\ No newline at end of file
+Compat issues with assembly System.ComponentModel.TypeConverter:
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 92
\ No newline at end of file
diff --git a/src/shims/ApiCompatBaseline.uap.netstandardOnly.txt b/src/shims/ApiCompatBaseline.uap.netstandardOnly.txt
index 5d2d2879f593..5a7c8acf8d6b 100644
--- a/src/shims/ApiCompatBaseline.uap.netstandardOnly.txt
+++ b/src/shims/ApiCompatBaseline.uap.netstandardOnly.txt
@@ -82,4 +82,10 @@ MembersMustExist : Member 'System.String.Chars.get(System.Range)' does not exist
 MembersMustExist : Member 'System.String.Substring(System.Index)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.String.Substring(System.Range)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Utf8String.Slice(System.Int32, System.Int32)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 83
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 89
diff --git a/src/shims/ApiCompatBaseline.uapaot.netstandard.txt b/src/shims/ApiCompatBaseline.uapaot.netstandard.txt
index 360298a12ef5..4560b09ab757 100644
--- a/src/shims/ApiCompatBaseline.uapaot.netstandard.txt
+++ b/src/shims/ApiCompatBaseline.uapaot.netstandard.txt
@@ -105,4 +105,11 @@ Compat issues with assembly System.Security.Cryptography.Pkcs:
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.Certificates.set(System.Security.Cryptography.X509Certificates.X509Certificate2Collection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.SignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Security.Cryptography.Pkcs.CmsSigner.UnsignedAttributes.set(System.Security.Cryptography.CryptographicAttributeObjectCollection)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 92
\ No newline at end of file
+Compat issues with assembly System.ComponentModel.TypeConverter:
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 98
\ No newline at end of file
diff --git a/src/shims/ApiCompatBaseline.uapaot.netstandardOnly.txt b/src/shims/ApiCompatBaseline.uapaot.netstandardOnly.txt
index e33ffe0f01a2..6615b50b17f6 100644
--- a/src/shims/ApiCompatBaseline.uapaot.netstandardOnly.txt
+++ b/src/shims/ApiCompatBaseline.uapaot.netstandardOnly.txt
@@ -71,4 +71,10 @@ MembersMustExist : Member 'System.Runtime.InteropServices.Marshal.GetTypedObject
 MembersMustExist : Member 'System.Runtime.InteropServices.Marshal.SetComObjectData(System.Object, System.Object, System.Object)' does not exist in the implementation but it does exist in the contract.
 CannotChangeAttribute : Attribute 'System.AttributeUsageAttribute' on 'System.Xml.Serialization.XmlAnyAttributeAttribute' changed from '[AttributeUsageAttribute(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue)]' in the contract to '[AttributeUsageAttribute(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple=false)]' in the implementation.
 CannotChangeAttribute : Attribute 'System.AttributeUsageAttribute' on 'System.Xml.Serialization.XmlNamespaceDeclarationsAttribute' changed from '[AttributeUsageAttribute(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue)]' in the contract to '[AttributeUsageAttribute(AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.ReturnValue, AllowMultiple=false)]' in the implementation.
-Total Issues: 71
+CannotSealType : Type 'System.ComponentModel.BaseNumberConverter' is effectively (has a private constructor) sealed in the implementation but not sealed in the contract.
+MembersMustExist : Member 'System.ComponentModel.BaseNumberConverter..ctor()' does not exist in the implementation but it does exist in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.CanConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertFrom(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object)' is non-virtual in the implementation but is virtual in the contract.
+CannotMakeMemberNonVirtual : Member 'System.ComponentModel.BaseNumberConverter.ConvertTo(System.ComponentModel.ITypeDescriptorContext, System.Globalization.CultureInfo, System.Object, System.Type)' is non-virtual in the implementation but is virtual in the contract.
+Total Issues: 77