diff --git a/src/Shared/Helpers/GeneratorUtilities.cs b/src/Shared/Helpers/GeneratorUtilities.cs
index 9108ab1..affe823 100644
--- a/src/Shared/Helpers/GeneratorUtilities.cs
+++ b/src/Shared/Helpers/GeneratorUtilities.cs
@@ -43,7 +43,8 @@ public static EquatableList<string> GetTypeDeclarations(ITypeSymbol type)
                 { IsRecord: true, IsValueType: true } => "record struct",
                 { IsRecord: true, IsValueType: false } => "record",
                 { IsRecord: false, IsValueType: true } => "struct",
-                { IsRecord: false, IsValueType: false } => "class",
+                { IsRecord: false, IsValueType: false, TypeKind: TypeKind.Class } => "class",
+                { IsRecord: false, IsValueType: false, TypeKind: TypeKind.Interface } => "interface",
                 _ => string.Empty
             };
 
diff --git a/src/Tests/Examples/Issue536.cs b/src/Tests/Examples/Issue536.cs
new file mode 100644
index 0000000..3e59a0d
--- /dev/null
+++ b/src/Tests/Examples/Issue536.cs
@@ -0,0 +1,8 @@
+public partial interface IInterface
+{
+    [AutoCtor.AutoConstruct]
+    public partial class NestedClass
+    {
+        public IInterface Item { get; }
+    }
+}
diff --git a/src/Tests/Examples/Issue536.cs#IInterface.NestedClass.g.verified.cs b/src/Tests/Examples/Issue536.cs#IInterface.NestedClass.g.verified.cs
new file mode 100644
index 0000000..385eba8
--- /dev/null
+++ b/src/Tests/Examples/Issue536.cs#IInterface.NestedClass.g.verified.cs
@@ -0,0 +1,21 @@
+//HintName: IInterface.NestedClass.g.cs
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by https://github.com/distantcam/AutoCtor
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+partial interface IInterface
+{
+	partial class NestedClass
+	{
+		[global::System.Runtime.CompilerServices.CompilerGenerated]
+		[global::System.CodeDom.Compiler.GeneratedCode("AutoCtor", "0.0.0.0")]
+		[global::System.Diagnostics.DebuggerNonUserCode]
+		[global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+		public NestedClass(global::IInterface item)
+		{
+			this.Item = item;
+		}
+	}
+}