diff --git a/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.00.verified.cs b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.00.verified.cs
new file mode 100644
index 0000000..653d24f
--- /dev/null
+++ b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.00.verified.cs
@@ -0,0 +1,23 @@
+//HintName: DiscriminatedUnionAttribute.g.cs
+// <auto-generated/>
+#nullable enable
+
+namespace Funcky
+{
+    [global::System.Diagnostics.Conditional("Funcky_DiscriminatedUnion")]
+    [global::System.AttributeUsage(global::System.AttributeTargets.Class)]
+    internal sealed class DiscriminatedUnionAttribute : global::System.Attribute
+    {
+        /// <summary>Allow only consumers in the same assembly to use the exhaustive <c>Match</c> and <c>Switch</c> methods.</summary>
+        public bool NonExhaustive { get; set; }
+
+        /// <summary>Generates exhaustive <c>Match</c> and <c>Switch</c> methods for the entire type hierarchy.</summary>
+        public bool Flatten { get; set; }
+
+        /// <summary>If a specialized partition extension method for <c>IEnumerable<YourType></c> should be generated. Defaults to <see langword="false"/>.</summary>
+        public bool GeneratePartitionExtension { get; set; }
+
+        /// <summary>Customized the generic type name used for the result in the generated <c>Match</c> methods. Defaults to <c>TResult</c>.</summary>
+        public string? MatchResultTypeName { get; set; }
+    }
+}
diff --git a/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.01.verified.cs b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.01.verified.cs
new file mode 100644
index 0000000..958c82b
--- /dev/null
+++ b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.GeneratesExpectedSourceCode_sourceFileName=FlattenedNestedUnionWithPartition.01.verified.cs
@@ -0,0 +1,65 @@
+//HintName: DiscriminatedUnionGenerator.g.cs
+// <auto-generated/>
+#nullable enable
+
+namespace Funcky.DiscriminatedUnion.Test
+{
+    partial record FlattenedNestedUnionWithPartition
+    {
+        [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+        public abstract TResult Match<TResult>(global::System.Func<Keyword, TResult> keyword, global::System.Func<Literal.Number.Integer, TResult> integer);
+        
+        [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+        public abstract void Switch(global::System.Action<Keyword> keyword, global::System.Action<Literal.Number.Integer> integer);
+        
+        partial record Keyword
+        {
+            [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+            public override TResult Match<TResult>(global::System.Func<Keyword, TResult> keyword, global::System.Func<Literal.Number.Integer, TResult> integer) => keyword(this);
+            
+            [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+            public override void Switch(global::System.Action<Keyword> keyword, global::System.Action<Literal.Number.Integer> integer) => keyword(this);
+        }
+        
+        partial record Literal
+        {
+            partial record Number
+            {
+                partial record Integer
+                {
+                    [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+                    public override TResult Match<TResult>(global::System.Func<Keyword, TResult> keyword, global::System.Func<Literal.Number.Integer, TResult> integer) => integer(this);
+                    
+                    [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+                    public override void Switch(global::System.Action<Keyword> keyword, global::System.Action<Literal.Number.Integer> integer) => integer(this);
+                }
+            }
+        }
+    }
+    
+    [global::System.CodeDom.Compiler.GeneratedCode("Funcky.DiscriminatedUnion.SourceGeneration", "1.2.0.0")]
+    public static partial class FlattenedNestedUnionWithPartitionEnumerableExtensions
+    {
+        public static (global::System.Collections.Generic.IReadOnlyList<FlattenedNestedUnionWithPartition.Keyword> keyword, global::System.Collections.Generic.IReadOnlyList<FlattenedNestedUnionWithPartition.Literal.Number.Integer> integer) Partition(this global::System.Collections.Generic.IEnumerable<FlattenedNestedUnionWithPartition> source)
+        {
+            var keywordItems = new global::System.Collections.Generic.List<FlattenedNestedUnionWithPartition.Keyword>();
+            var integerItems = new global::System.Collections.Generic.List<FlattenedNestedUnionWithPartition.Literal.Number.Integer>();
+            foreach (var item in source)
+            {
+                item.Switch(keyword: keywordItems.Add, integer: integerItems.Add);
+            }
+            return (keywordItems.AsReadOnly(), integerItems.AsReadOnly());
+        }
+        
+        public static TResult Partition<TResult>(this global::System.Collections.Generic.IEnumerable<FlattenedNestedUnionWithPartition> source, global::System.Func<global::System.Collections.Generic.IReadOnlyList<FlattenedNestedUnionWithPartition.Keyword>, global::System.Collections.Generic.IReadOnlyList<FlattenedNestedUnionWithPartition.Literal.Number.Integer>, TResult> resultSelector)
+        {
+            var keywordItems = new global::System.Collections.Generic.List<FlattenedNestedUnionWithPartition.Keyword>();
+            var integerItems = new global::System.Collections.Generic.List<FlattenedNestedUnionWithPartition.Literal.Number.Integer>();
+            foreach (var item in source)
+            {
+                item.Switch(keyword: keywordItems.Add, integer: integerItems.Add);
+            }
+            return resultSelector(keywordItems.AsReadOnly(), integerItems.AsReadOnly());
+        }
+    }
+}
diff --git a/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.cs b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.cs
index ca18156..c90b294 100644
--- a/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.cs
+++ b/Funcky.DiscriminatedUnion.Test/SourceGeneratorTest.cs
@@ -22,6 +22,7 @@ public sealed class SourceGeneratorTest
     [InlineData("JsonPolymorphic")]
     [InlineData("UnionWithPartitionUsage")]
     [InlineData("FlattenedUnionWithPartition")]
+    [InlineData("FlattenedNestedUnionWithPartition")]
     public async Task GeneratesExpectedSourceCode(string sourceFileName) => await Verify(sourceFileName);
 
     [Fact]
diff --git a/Funcky.DiscriminatedUnion.Test/Sources/FlattenedNestedUnionWithPartition.cs b/Funcky.DiscriminatedUnion.Test/Sources/FlattenedNestedUnionWithPartition.cs
new file mode 100644
index 0000000..08da131
--- /dev/null
+++ b/Funcky.DiscriminatedUnion.Test/Sources/FlattenedNestedUnionWithPartition.cs
@@ -0,0 +1,23 @@
+namespace Funcky.DiscriminatedUnion.Test;
+
+[DiscriminatedUnion(Flatten = true, GeneratePartitionExtension = true)]
+public abstract partial record FlattenedNestedUnionWithPartition
+{
+    public sealed partial record Keyword(string Value) : FlattenedNestedUnionWithPartition;
+
+    public abstract partial record Literal : FlattenedNestedUnionWithPartition
+    {
+        public abstract partial record Number : Literal
+        {
+            public sealed partial record Integer(int Value) : Number;
+        }
+    }
+}
+
+public static class FlattenedNestedUnionWithPartitionTest
+{
+    public static void Test(FlattenedNestedUnionWithPartition[] items)
+    {
+        var (keywords, integers) = items.Partition();
+    }
+}