diff --git a/crates/csharp/src/csproj.rs b/crates/csharp/src/csproj.rs
index 76b8c5d57..9be60a0f1 100644
--- a/crates/csharp/src/csproj.rs
+++ b/crates/csharp/src/csproj.rs
@@ -12,6 +12,7 @@ pub struct CSProjectLLVMBuilder {
     clean_targets: bool,
     world_name: String,
     binary: bool,
+    skip_wit_component: bool,
 }
 
 pub struct CSProjectMonoBuilder {
@@ -31,6 +32,7 @@ impl CSProject {
             clean_targets: false,
             world_name: world_name.to_string(),
             binary: false,
+            skip_wit_component: false,
         }
     }
 
@@ -69,6 +71,14 @@ impl CSProjectLLVMBuilder {
             "<OutputType>Library</OutputType>"
         };
 
+        let component_type_linker_arg = if self.skip_wit_component {
+            "<CustomLinkerArg Include=\"-Wl,--skip-wit-component\" />".to_string()
+        } else {
+            format!(
+                "<CustomLinkerArg Include=\"-Wl,--component-type,{camel}_component_type.wit\" />"
+            )
+        };
+
         let mut csproj = format!(
             "<Project Sdk=\"Microsoft.NET.Sdk\">
 
@@ -94,7 +104,7 @@ impl CSProjectLLVMBuilder {
         </ItemGroup>
 
         <ItemGroup>
-            <CustomLinkerArg Include=\"-Wl,--component-type,{camel}_component_type.wit\" />
+            {component_type_linker_arg}
         </ItemGroup>
         "
         );
@@ -178,6 +188,10 @@ impl CSProjectLLVMBuilder {
         self.binary = true;
     }
 
+    pub fn skip_wit_component(&mut self) {
+        self.skip_wit_component = true;
+    }
+
     pub fn clean(&mut self) -> &mut Self {
         self.clean_targets = true;
 
diff --git a/crates/test/src/csharp.rs b/crates/test/src/csharp.rs
index 8e11ca7f7..53032296e 100644
--- a/crates/test/src/csharp.rs
+++ b/crates/test/src/csharp.rs
@@ -1,6 +1,7 @@
 use crate::{Compile, LanguageMethods, Runner, Verify};
 use anyhow::Result;
 use heck::*;
+use serde::Deserialize;
 use std::env;
 use std::fs;
 use std::path::Path;
@@ -8,6 +9,12 @@ use std::process::Command;
 
 pub struct Csharp;
 
+#[derive(Default, Deserialize)]
+#[serde(deny_unknown_fields, rename_all = "kebab-case")]
+struct LangConfig {
+    skip_wit_component: bool,
+}
+
 fn dotnet() -> Command {
     let dotnet_cmd = match env::var("DOTNET_ROOT") {
         Ok(val) => Path::new(&val).join("dotnet"),
@@ -59,6 +66,7 @@ impl LanguageMethods for Csharp {
     }
 
     fn compile(&self, runner: &Runner, compile: &Compile<'_>) -> Result<()> {
+        let config = compile.component.deserialize_lang_config::<LangConfig>()?;
         let world_name = &compile.component.bindgen.world;
         let path = &compile.component.path;
         let test_dir = &compile.bindings_dir;
@@ -75,6 +83,9 @@ impl LanguageMethods for Csharp {
         let mut csproj =
             wit_bindgen_csharp::CSProject::new(test_dir.to_path_buf(), &assembly_name, world_name);
         csproj.aot();
+        if config.skip_wit_component {
+            csproj.skip_wit_component();
+        }
         csproj.generate()?;
 
         let mut cmd = dotnet();
@@ -109,7 +120,11 @@ impl LanguageMethods for Csharp {
 
         runner.run_command(&mut cmd)?;
 
-        fs::copy(&wasm_filename, &compile.output)?;
+        if config.skip_wit_component {
+            runner.convert_p1_to_component_appending_type_metadata(&wasm_filename, compile)?;
+        } else {
+            fs::copy(&wasm_filename, &compile.output)?;
+        }
 
         Ok(())
     }
diff --git a/crates/test/src/lib.rs b/crates/test/src/lib.rs
index 615fb9ce0..e65f91606 100644
--- a/crates/test/src/lib.rs
+++ b/crates/test/src/lib.rs
@@ -1081,6 +1081,30 @@ status: {}",
     ///
     /// Stores the output at `compile.output`.
     fn convert_p1_to_component(&self, p1: &Path, compile: &Compile<'_>) -> Result<()> {
+        self.convert_p1_to_component_impl(p1, compile, false)
+    }
+
+    /// Converts the WASIp1 module at `p1` to a component, appending component
+    /// type metadata from the test WIT even if existing metadata is present.
+    ///
+    /// Some toolchains emit incomplete or stale component type metadata even
+    /// when asked to skip componentization, while still needing their own
+    /// metadata for WASI imports. Use this when the test harness must add
+    /// guest-world metadata without discarding toolchain metadata.
+    fn convert_p1_to_component_appending_type_metadata(
+        &self,
+        p1: &Path,
+        compile: &Compile<'_>,
+    ) -> Result<()> {
+        self.convert_p1_to_component_impl(p1, compile, true)
+    }
+
+    fn convert_p1_to_component_impl(
+        &self,
+        p1: &Path,
+        compile: &Compile<'_>,
+        append_component_type: bool,
+    ) -> Result<()> {
         let mut resolve = wit_parser::Resolve::default();
         let (pkg, _) = resolve
             .push_path(&compile.component.bindgen.wit_path)
@@ -1088,7 +1112,7 @@ status: {}",
         let world = resolve.select_world(&[pkg], Some(&compile.component.bindgen.world))?;
         let mut module = fs::read(&p1).context("failed to read wasm file")?;
 
-        if !has_component_type_sections(&module) {
+        if append_component_type || !has_component_type_sections(&module) {
             let encoded =
                 wit_component::metadata::encode(&resolve, world, StringEncoding::UTF8, None)?;
             let section = wasm_encoder::CustomSection {
diff --git a/tests/runtime/map/test.cs b/tests/runtime/map/test.cs
new file mode 100644
index 000000000..e4e63bf5a
--- /dev/null
+++ b/tests/runtime/map/test.cs
@@ -0,0 +1,123 @@
+//@ wasmtime-flags = '-Wcomponent-model-map'
+//@ [lang]
+//@ skip-wit-component = true
+
+using System.Diagnostics;
+using System.Text;
+
+namespace TestWorld.wit.Exports.test.maps
+{
+    public class ToTestExportsImpl : IToTestExports
+    {
+        public static Dictionary<string, uint> NamedRoundtrip(Dictionary<uint, string> a)
+        {
+            Debug.Assert(a.Count == 2);
+            Debug.Assert(a[1] == "uno");
+            Debug.Assert(a[2] == "two");
+
+            return a.ToDictionary(entry => entry.Value, entry => entry.Key);
+        }
+
+        public static Dictionary<string, byte[]> BytesRoundtrip(Dictionary<string, byte[]> a)
+        {
+            Debug.Assert(a.Count == 2);
+            Debug.Assert(a["hello"].SequenceEqual(Encoding.UTF8.GetBytes("world")));
+            Debug.Assert(a["bin"].SequenceEqual(new byte[] { 0, 1, 2 }));
+
+            return a;
+        }
+
+        public static Dictionary<uint, string> EmptyRoundtrip(Dictionary<uint, string> a)
+        {
+            Debug.Assert(a.Count == 0);
+            return a;
+        }
+
+        public static Dictionary<string, uint?> OptionRoundtrip(Dictionary<string, uint?> a)
+        {
+            Debug.Assert(a.Count == 2);
+            Debug.Assert(a["some"] == 42);
+            Debug.Assert(a["none"] == null);
+
+            return a;
+        }
+
+        public static IToTestExports.LabeledEntry RecordRoundtrip(IToTestExports.LabeledEntry a)
+        {
+            Debug.Assert(a.label == "test-label");
+            Debug.Assert(a.values.Count == 2);
+            Debug.Assert(a.values[10] == "ten");
+            Debug.Assert(a.values[20] == "twenty");
+
+            return a;
+        }
+
+        public static Dictionary<string, uint> InlineRoundtrip(Dictionary<uint, string> a)
+        {
+            return a.ToDictionary(entry => entry.Value, entry => entry.Key);
+        }
+
+        public static Dictionary<uint, string> LargeRoundtrip(Dictionary<uint, string> a)
+        {
+            Debug.Assert(a.Count == 100);
+            return a;
+        }
+
+        public static (Dictionary<string, uint>, Dictionary<string, byte[]>) MultiParamRoundtrip(
+            Dictionary<uint, string> a,
+            Dictionary<string, byte[]> b)
+        {
+            Debug.Assert(a.Count == 2);
+            Debug.Assert(b.Count == 1);
+
+            return (a.ToDictionary(entry => entry.Value, entry => entry.Key), b);
+        }
+
+        public static Dictionary<string, Dictionary<uint, string>> NestedRoundtrip(
+            Dictionary<string, Dictionary<uint, string>> a)
+        {
+            Debug.Assert(a.Count == 2);
+            Debug.Assert(a["group-a"].Count == 2);
+            Debug.Assert(a["group-a"][1] == "one");
+            Debug.Assert(a["group-a"][2] == "two");
+            Debug.Assert(a["group-b"].Count == 1);
+            Debug.Assert(a["group-b"][10] == "ten");
+
+            return a;
+        }
+
+        public static IToTestExports.MapOrString VariantRoundtrip(IToTestExports.MapOrString a)
+        {
+            return a;
+        }
+
+        public static Dictionary<uint, string> ResultRoundtrip(
+            Result<Dictionary<uint, string>, string> a)
+        {
+            if (a.IsErr)
+            {
+                throw new WitException<string>(a.AsErr, 0);
+            }
+
+            return a.AsOk;
+        }
+
+        public static (Dictionary<uint, string>, ulong) TupleRoundtrip(
+            (Dictionary<uint, string>, ulong) a)
+        {
+            Debug.Assert(a.Item1.Count == 1);
+            Debug.Assert(a.Item1[7] == "seven");
+            Debug.Assert(a.Item2 == 42);
+
+            return a;
+        }
+
+        public static Dictionary<uint, string> SingleEntryRoundtrip(Dictionary<uint, string> a)
+        {
+            Debug.Assert(a.Count == 1);
+            Debug.Assert(a[99] == "ninety-nine");
+
+            return a;
+        }
+    }
+}