diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1da50a845ef..8020b205688 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -90,6 +90,9 @@
 
 * Fix MDN links to static interface methods.
   [#4010](https://github.com/rustwasm/wasm-bindgen/pull/4010)
+ 
+* Fixed Deno support.
+  [#3990](https://github.com/rustwasm/wasm-bindgen/pull/3990)
 
 --------------------------------------------------------------------------------
 
diff --git a/crates/cli-support/src/js/mod.rs b/crates/cli-support/src/js/mod.rs
index 97a7cbd8044..8604d6f2a9c 100644
--- a/crates/cli-support/src/js/mod.rs
+++ b/crates/cli-support/src/js/mod.rs
@@ -345,7 +345,8 @@ impl<'a> Context<'a> {
             }}
 
             const wasmInstance = (await WebAssembly.instantiate(wasmCode, imports)).instance;
-            const wasm = wasmInstance.exports;",
+            const wasm = wasmInstance.exports;
+            export const __wasm = wasm;",
             module_name = module_name
         )
     }
diff --git a/crates/cli/src/bin/wasm-bindgen-test-runner/deno.rs b/crates/cli/src/bin/wasm-bindgen-test-runner/deno.rs
index a0b05cdbd5b..390b2761512 100644
--- a/crates/cli/src/bin/wasm-bindgen-test-runner/deno.rs
+++ b/crates/cli/src/bin/wasm-bindgen-test-runner/deno.rs
@@ -18,16 +18,13 @@ pub fn execute(
 
         {console_override}
 
-        // global.__wbg_test_invoke = f => f();
+        window.__wbg_test_invoke = f => f();
 
         // Forward runtime arguments. These arguments are also arguments to the
         // `wasm-bindgen-test-runner` which forwards them to deno which we
         // forward to the test harness. this is basically only used for test
         // filters for now.
-        cx.args(Deno.args.slice(1));
-
-        const ok = await cx.run(tests.map(n => wasm.__wasm[n]));
-        if (!ok) Deno.exit(1);
+        cx.args(Deno.args);
 
         const tests = [];
     "#,
@@ -39,6 +36,11 @@ pub fn execute(
         js_to_execute.push_str(&format!("tests.push('{}')\n", test));
     }
 
+    js_to_execute.push_str(
+        r#"const ok = await cx.run(tests.map(n => wasm.__wasm[n]));
+if (!ok) Deno.exit(1);"#,
+    );
+
     let js_path = tmpdir.join("run.js");
     fs::write(&js_path, js_to_execute).context("failed to write JS file")?;
 
diff --git a/crates/cli/src/bin/wasm-bindgen-test-runner/headless.rs b/crates/cli/src/bin/wasm-bindgen-test-runner/headless.rs
index f111902f73f..a4886800260 100644
--- a/crates/cli/src/bin/wasm-bindgen-test-runner/headless.rs
+++ b/crates/cli/src/bin/wasm-bindgen-test-runner/headless.rs
@@ -3,7 +3,7 @@ use anyhow::{bail, format_err, Context, Error};
 use log::{debug, warn};
 use rouille::url::Url;
 use serde::{Deserialize, Serialize};
-use serde_json::{self, json, Map, Value as Json};
+use serde_json::{json, Map, Value as Json};
 use std::env;
 use std::fs::File;
 use std::io::{self, Read};
diff --git a/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs b/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
index c90d00251ba..0e1718119ae 100644
--- a/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
+++ b/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
@@ -30,7 +30,7 @@ wrap("info");
 wrap("warn");
 wrap("error");
 
-cx = new wasm.WasmBindgenTestContext();
+const cx = new wasm.WasmBindgenTestContext();
 handlers.on_console_debug = wasm.__wbgtest_console_debug;
 handlers.on_console_log = wasm.__wbgtest_console_log;
 handlers.on_console_info = wasm.__wbgtest_console_info;
@@ -117,7 +117,10 @@ pub fn execute(
 #[cfg(unix)]
 pub fn exec(cmd: &mut Command) -> Result<(), Error> {
     use std::os::unix::prelude::*;
-    Err(Error::from(cmd.exec()).context("failed to execute `node`"))
+    Err(Error::from(cmd.exec()).context(format!(
+        "failed to execute `{}`",
+        cmd.get_program().to_string_lossy()
+    )))
 }
 
 #[cfg(windows)]
diff --git a/crates/test/src/rt/detect.rs b/crates/test/src/rt/detect.rs
index 235b14c67d6..f4cdd988d59 100644
--- a/crates/test/src/rt/detect.rs
+++ b/crates/test/src/rt/detect.rs
@@ -12,6 +12,11 @@ extern "C" {
     #[wasm_bindgen(method, getter, structural)]
     fn constructor(me: &Scope) -> Constructor;
 
+    #[wasm_bindgen(method, getter, structural, js_name = Deno)]
+    fn deno(me: &Scope) -> Option<Deno>;
+
+    type Deno;
+
     type Constructor;
     #[wasm_bindgen(method, getter, structural)]
     fn name(me: &Constructor) -> String;
@@ -27,7 +32,10 @@ pub fn detect() -> Runtime {
             "DedicatedWorkerGlobalScope"
             | "SharedWorkerGlobalScope"
             | "ServiceWorkerGlobalScope" => Runtime::Worker,
-            _ => Runtime::Browser,
+            _ => match scope.deno() {
+                Some(_) => Runtime::Node,
+                _ => Runtime::Browser,
+            },
         },
         None => Runtime::Node,
     }