diff --git a/TestComponentCSharp/Class.cpp b/TestComponentCSharp/Class.cpp
index ac6248a24..b14a02f30 100644
--- a/TestComponentCSharp/Class.cpp
+++ b/TestComponentCSharp/Class.cpp
@@ -481,6 +481,34 @@ namespace winrt::TestComponentCSharp::implementation
     {
         _objectIterableChanged.remove(token);
     }
+    IIterable<IIterable<WF::Point>> Class::IterableOfPointIterablesProperty()
+    {
+        return _pointIterableIterable;
+    }
+    void Class::IterableOfPointIterablesProperty(IIterable<IIterable<WF::Point>> const& value)
+    {
+        for (auto points : value)
+        {
+            for (auto point : points)
+            {
+            }
+        }
+        _pointIterableIterable = value;
+    }
+    IIterable<IIterable<WF::IInspectable>> Class::IterableOfObjectIterablesProperty()
+    {
+        return _objectIterableIterable;
+    }
+    void Class::IterableOfObjectIterablesProperty(IIterable<IIterable<WF::IInspectable>> const& value)
+    {
+        for (auto objects : value)
+        {
+            for (auto object : objects)
+            {
+            }
+        }
+        _objectIterableIterable = value;
+    }
     Uri Class::UriProperty()
     {
         return _uri;
diff --git a/TestComponentCSharp/Class.h b/TestComponentCSharp/Class.h
index 7eae0b447..c2039f632 100644
--- a/TestComponentCSharp/Class.h
+++ b/TestComponentCSharp/Class.h
@@ -37,6 +37,8 @@ namespace winrt::TestComponentCSharp::implementation
         Windows::Foundation::IInspectable _object;
         winrt::event<Windows::Foundation::EventHandler<Windows::Foundation::IInspectable>> _objectChanged;
         Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable> _objectIterable;
+        Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::Point>> _pointIterableIterable;
+        Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable>> _objectIterableIterable;
         winrt::event<Windows::Foundation::EventHandler<Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable>>> _objectIterableChanged;
         Windows::Foundation::Uri _uri;
         winrt::event<Windows::Foundation::EventHandler<Windows::Foundation::Uri>> _uriChanged;
@@ -153,6 +155,10 @@ namespace winrt::TestComponentCSharp::implementation
         void CallForObjectIterable(TestComponentCSharp::ProvideObjectIterable const& provideObjectIterable);
         winrt::event_token ObjectIterablePropertyChanged(Windows::Foundation::EventHandler<Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable>> const& handler);
         void ObjectIterablePropertyChanged(winrt::event_token const& token) noexcept;
+        Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::Point>> IterableOfPointIterablesProperty();
+        void IterableOfPointIterablesProperty(Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::Point>> const& value);
+        Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable>> IterableOfObjectIterablesProperty();
+        void IterableOfObjectIterablesProperty(Windows::Foundation::Collections::IIterable<Windows::Foundation::Collections::IIterable<Windows::Foundation::IInspectable>> const& value);
         Windows::Foundation::Uri UriProperty();
         void UriProperty(Windows::Foundation::Uri const& value);
         void RaiseUriChanged();
diff --git a/TestComponentCSharp/TestComponentCSharp.idl b/TestComponentCSharp/TestComponentCSharp.idl
index 55815cdae..4d1148cdc 100644
--- a/TestComponentCSharp/TestComponentCSharp.idl
+++ b/TestComponentCSharp/TestComponentCSharp.idl
@@ -176,6 +176,8 @@ namespace TestComponentCSharp
         void RaiseObjectIterableChanged();
         void CallForObjectIterable(ProvideObjectIterable provideObjectIterable);
         event Windows.Foundation.EventHandler<Windows.Foundation.Collections.IIterable<Object> > ObjectIterablePropertyChanged;
+        Windows.Foundation.Collections.IIterable<Windows.Foundation.Collections.IIterable<Windows.Foundation.Point> > IterableOfPointIterablesProperty;
+        Windows.Foundation.Collections.IIterable<Windows.Foundation.Collections.IIterable<Object> > IterableOfObjectIterablesProperty;
 
         Windows.Foundation.Uri UriProperty;
         void RaiseUriChanged();
diff --git a/UnitTest/TestComponentCSharp_Tests.cs b/UnitTest/TestComponentCSharp_Tests.cs
index 69cd6b8d0..474e44bf6 100644
--- a/UnitTest/TestComponentCSharp_Tests.cs
+++ b/UnitTest/TestComponentCSharp_Tests.cs
@@ -687,7 +687,26 @@ public void TestObjectCasting()
 
             var objects = new List<ManagedType>() { new ManagedType(), new ManagedType() };
             var query = from item in objects select item;
-            TestObject.ObjectIterableProperty = query;
+            TestObject.ObjectIterableProperty = query;
+
+            TestObject.ObjectProperty = "test";
+            Assert.Equal("test", TestObject.ObjectProperty);
+
+            var objectArray = new ManagedType[] { new ManagedType(), new ManagedType() };
+            TestObject.ObjectIterableProperty = objectArray;
+            Assert.True(TestObject.ObjectIterableProperty.SequenceEqual(objectArray));
+
+            var strArray = new string[] { "str1", "str2", "str3" };
+            TestObject.ObjectIterableProperty = strArray;
+            Assert.True(TestObject.ObjectIterableProperty.SequenceEqual(strArray));
+
+            var uriArray = new Uri[] { new Uri("http://aka.ms/cswinrt"), new Uri("http://github.com") };
+            TestObject.ObjectIterableProperty = uriArray;
+            Assert.True(TestObject.ObjectIterableProperty.SequenceEqual(uriArray));
+
+            var objectUriArray = new object[] { new Uri("http://github.com") };
+            TestObject.ObjectIterableProperty = objectUriArray;
+            Assert.True(TestObject.ObjectIterableProperty.SequenceEqual(objectUriArray));
         }
 
         [Fact]
@@ -2250,6 +2269,26 @@ public void TestIBindableVector()
         {
             CustomBindableVectorTest vector = new CustomBindableVectorTest();
             Assert.NotNull(vector);
+        }
+
+        [Fact]
+        public void TestCovariance()
+        {
+            var listOfListOfPoints = new List<List<Point>>() {
+                new List<Point>{ new Point(1, 1), new Point(1, 2), new Point(1, 3) },
+                new List<Point>{ new Point(2, 1), new Point(2, 2), new Point(2, 3) },
+                new List<Point>{ new Point(3, 1), new Point(3, 2), new Point(3, 3) }
+            };
+            TestObject.IterableOfPointIterablesProperty = listOfListOfPoints;
+            Assert.True(TestObject.IterableOfPointIterablesProperty.SequenceEqual(listOfListOfPoints));
+
+            var listOfListOfUris = new List<List<Uri>>() {
+                new List<Uri>{ new Uri("http://aka.ms/cswinrt"), new Uri("http://github.com") },
+                new List<Uri>{ new Uri("http://aka.ms/cswinrt") },
+                new List<Uri>{ new Uri("http://aka.ms/cswinrt"), new Uri("http://microsoft.com") }
+            };
+            TestObject.IterableOfObjectIterablesProperty = listOfListOfUris;
+            Assert.True(TestObject.IterableOfObjectIterablesProperty.SequenceEqual(listOfListOfUris));
         }
     }
 }
\ No newline at end of file
diff --git a/WinRT.Runtime/ComWrappersSupport.cs b/WinRT.Runtime/ComWrappersSupport.cs
index 347a09247..0f5e8f329 100644
--- a/WinRT.Runtime/ComWrappersSupport.cs
+++ b/WinRT.Runtime/ComWrappersSupport.cs
@@ -107,14 +107,17 @@ internal static List<ComInterfaceEntry> GetInterfaceTableEntries(object obj)
                 }
 
                 if (iface.IsConstructedGenericType
-                    && Projections.TryGetCompatibleWindowsRuntimeTypeForVariantType(iface, out var compatibleIface))
+                    && Projections.TryGetCompatibleWindowsRuntimeTypesForVariantType(iface, out var compatibleIfaces))
                 {
-                    var compatibleIfaceAbiType = compatibleIface.FindHelperType();
-                    entries.Add(new ComInterfaceEntry
+                    foreach (var compatibleIface in compatibleIfaces)
                     {
-                        IID = GuidGenerator.GetIID(compatibleIfaceAbiType),
-                        Vtable = (IntPtr)compatibleIfaceAbiType.GetAbiToProjectionVftblPtr()
-                    });
+                        var compatibleIfaceAbiType = compatibleIface.FindHelperType();
+                        entries.Add(new ComInterfaceEntry
+                        {
+                            IID = GuidGenerator.GetIID(compatibleIfaceAbiType),
+                            Vtable = (IntPtr)compatibleIfaceAbiType.GetAbiToProjectionVftblPtr()
+                        });
+                    }
                 }
             }
 
diff --git a/WinRT.Runtime/Projections.cs b/WinRT.Runtime/Projections.cs
index 06b06c9ca..6c345c53d 100644
--- a/WinRT.Runtime/Projections.cs
+++ b/WinRT.Runtime/Projections.cs
@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
+using System.Linq;
 using System.Numerics;
 using System.Reflection;
 using System.Threading;
@@ -206,6 +207,7 @@ private static bool IsTypeWindowsRuntimeTypeNoArray(Type type)
                 || type.GetCustomAttribute<WindowsRuntimeTypeAttribute>() is object;
         }
 
+        // Use TryGetCompatibleWindowsRuntimeTypesForVariantType instead.
         public static bool TryGetCompatibleWindowsRuntimeTypeForVariantType(Type type, out Type compatibleType)
         {
             compatibleType = null;
@@ -247,6 +249,118 @@ public static bool TryGetCompatibleWindowsRuntimeTypeForVariantType(Type type, o
             return true;
         }
 
+        private static HashSet<Type> GetCompatibleTypes(Type type)
+        {
+            HashSet<Type> compatibleTypes = new HashSet<Type>();
+
+            foreach (var iface in type.GetInterfaces())
+            {
+                if (IsTypeWindowsRuntimeTypeNoArray(iface))
+                {
+                    compatibleTypes.Add(iface);
+                }
+
+                if (iface.IsConstructedGenericType
+                    && TryGetCompatibleWindowsRuntimeTypesForVariantType(iface, out var compatibleIfaces))
+                {
+                    compatibleTypes.UnionWith(compatibleIfaces);
+                }
+            }
+
+            Type baseType = type.BaseType;
+            while (baseType != null)
+            {
+                if (IsTypeWindowsRuntimeTypeNoArray(baseType))
+                {
+                    compatibleTypes.Add(baseType);
+                }
+                baseType = baseType.BaseType;
+            }
+
+            return compatibleTypes;
+        }
+
+        internal static IEnumerable<Type> GetAllPossibleTypeCombinations(IEnumerable<IEnumerable<Type>> compatibleTypesPerGeneric, Type definition)
+        {
+            // Implementation adapted from https://stackoverflow.com/a/4424005
+            var accum = new List<Type>();
+            var compatibleTypesPerGenericArray = compatibleTypesPerGeneric.ToArray();
+            if (compatibleTypesPerGenericArray.Length > 0)
+            {
+                GetAllPossibleTypeCombinationsCore(
+                    accum,
+                    new Stack<Type>(),
+                    compatibleTypesPerGenericArray,
+                    compatibleTypesPerGenericArray.Length - 1);
+            }
+            return accum;
+
+            void GetAllPossibleTypeCombinationsCore(List<Type> accum, Stack<Type> stack, IEnumerable<Type>[] compatibleTypes, int index)
+            {
+                foreach (var type in compatibleTypes[index])
+                {
+                    stack.Push(type);
+                    if (index == 0)
+                    {
+                        // IEnumerable on a System.Collections.Generic.Stack
+                        // enumerates in order of removal (last to first).
+                        // As a result, we get the correct ordering here.
+                        accum.Add(definition.MakeGenericType(stack.ToArray()));
+                    }
+                    else
+                    {
+                        GetAllPossibleTypeCombinationsCore(accum, stack, compatibleTypes, index - 1);
+                    }
+                    stack.Pop();
+                }
+            }
+        }
+
+        internal static bool TryGetCompatibleWindowsRuntimeTypesForVariantType(Type type, out IEnumerable<Type> compatibleTypes)
+        {
+            compatibleTypes = null;
+            if (!type.IsConstructedGenericType)
+            {
+                throw new ArgumentException(nameof(type));
+            }
+
+            var definition = type.GetGenericTypeDefinition();
+
+            if (!IsTypeWindowsRuntimeTypeNoArray(definition))
+            {
+                return false;
+            }
+
+            var genericConstraints = definition.GetGenericArguments();
+            var genericArguments = type.GetGenericArguments();
+            List<List<Type>> compatibleTypesPerGeneric = new List<List<Type>>();
+            for (int i = 0; i < genericArguments.Length; i++)
+            {
+                List<Type> compatibleTypesForGeneric = new List<Type>();
+                bool argumentCovariantObject = (genericConstraints[i].GenericParameterAttributes & GenericParameterAttributes.VarianceMask) == GenericParameterAttributes.Covariant
+                    && !genericArguments[i].IsValueType;
+
+                if (IsTypeWindowsRuntimeTypeNoArray(genericArguments[i]))
+                {
+                    compatibleTypesForGeneric.Add(genericArguments[i]);
+                }
+                else if (!argumentCovariantObject)
+                {
+                    return false;
+                }
+
+                if (argumentCovariantObject)
+                {
+                    compatibleTypesForGeneric.AddRange(GetCompatibleTypes(genericArguments[i]));
+                }
+
+                compatibleTypesPerGeneric.Add(compatibleTypesForGeneric);
+            }
+
+            compatibleTypes = GetAllPossibleTypeCombinations(compatibleTypesPerGeneric, definition);
+            return true;
+        }
+
         internal static bool TryGetDefaultInterfaceTypeForRuntimeClassType(Type runtimeClass, out Type defaultInterface)
         {
             runtimeClass = runtimeClass.GetRuntimeClassCCWType() ?? runtimeClass;