diff --git a/Cargo.lock b/Cargo.lock
index 2b052373ffc20e..16173cfd199457 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5189,9 +5189,9 @@ dependencies = [
 
 [[package]]
 name = "v8"
-version = "0.47.1"
+version = "0.48.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be156dece7a023d5959a72dc0d398d6c95100ec601a2cea10d868da143e85166"
+checksum = "3734ddf37e06e5020a1d5c969301be0cdf023cde0ef4257248ff19eb3a7223e3"
 dependencies = [
  "bitflags",
  "fslock",
diff --git a/cli/tests/testdata/worker_close_in_wasm_reactions.js.out b/cli/tests/testdata/worker_close_in_wasm_reactions.js.out
index eef017a96f4d5c..6485c620e5c3dc 100644
--- a/cli/tests/testdata/worker_close_in_wasm_reactions.js.out
+++ b/cli/tests/testdata/worker_close_in_wasm_reactions.js.out
@@ -1 +1 @@
-Error: CompileError: WebAssembly.compile(): expected string length @+10
+Error: CompileError: WebAssembly.compile(): expected  length: @+10
diff --git a/core/Cargo.toml b/core/Cargo.toml
index 7f9b5072f32e75..61c38521d90cd5 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -33,7 +33,7 @@ serde_json = { version = "1.0.79", features = ["preserve_order"] }
 serde_v8 = { version = "0.58.0", path = "../serde_v8" }
 sourcemap = "=6.0.1"
 url = { version = "2.2.2", features = ["serde"] }
-v8 = { version = "0.47.1", default-features = false }
+v8 = { version = "0.48.1", default-features = false }
 
 [[example]]
 name = "http_bench_json_ops"
diff --git a/core/bindings.rs b/core/bindings.rs
index aef479472caa66..f3c16acbff6ecc 100644
--- a/core/bindings.rs
+++ b/core/bindings.rs
@@ -140,6 +140,22 @@ pub fn set_func_raw(
   obj.set(scope, key.into(), val.into());
 }
 
+pub extern "C" fn wasm_async_resolve_promise_callback(
+  _isolate: *mut v8::Isolate,
+  context: v8::Local<v8::Context>,
+  resolver: v8::Local<v8::PromiseResolver>,
+  compilation_result: v8::Local<v8::Value>,
+  success: v8::WasmAsyncSuccess,
+) {
+  // SAFETY: `CallbackScope` can be safely constructed from `Local<Context>`
+  let scope = &mut unsafe { v8::CallbackScope::new(context) };
+  if success == v8::WasmAsyncSuccess::Success {
+    resolver.resolve(scope, compilation_result).unwrap();
+  } else {
+    resolver.reject(scope, compilation_result).unwrap();
+  }
+}
+
 pub extern "C" fn host_import_module_dynamically_callback(
   context: v8::Local<v8::Context>,
   _host_defined_options: v8::Local<v8::Data>,
diff --git a/core/runtime.rs b/core/runtime.rs
index 541aa7c021a8b1..7f113223f3690f 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -227,11 +227,6 @@ fn v8_init(
   static ICU_DATA: IcuData = IcuData(*include_bytes!("icudtl.dat"));
   v8::icu::set_common_data_71(&ICU_DATA.0).unwrap();
 
-  let v8_platform = v8_platform
-    .unwrap_or_else(|| v8::new_default_platform(0, false).make_shared());
-  v8::V8::initialize_platform(v8_platform);
-  v8::V8::initialize();
-
   let flags = concat!(
     " --experimental-wasm-threads",
     " --wasm-test-streaming",
@@ -248,6 +243,11 @@ fn v8_init(
   } else {
     v8::V8::set_flags_from_string(flags);
   }
+
+  let v8_platform = v8_platform
+    .unwrap_or_else(|| v8::new_default_platform(0, false).make_shared());
+  v8::V8::initialize_platform(v8_platform);
+  v8::V8::initialize();
 }
 
 #[derive(Default)]
@@ -516,6 +516,9 @@ impl JsRuntime {
     isolate.set_host_import_module_dynamically_callback(
       bindings::host_import_module_dynamically_callback,
     );
+    isolate.set_wasm_async_resolve_promise_callback(
+      bindings::wasm_async_resolve_promise_callback,
+    );
     isolate
   }
 
diff --git a/serde_v8/Cargo.toml b/serde_v8/Cargo.toml
index a5a144151ee6a0..38e0678578f3d3 100644
--- a/serde_v8/Cargo.toml
+++ b/serde_v8/Cargo.toml
@@ -18,7 +18,7 @@ derive_more = "0.99.17"
 serde = { version = "1.0.136", features = ["derive"] }
 serde_bytes = "0.11"
 smallvec = { version = "1.8", features = ["union"] }
-v8 = { version = "0.47.1", default-features = false }
+v8 = { version = "0.48.1", default-features = false }
 
 [dev-dependencies]
 bencher = "0.1"
diff --git a/tools/wpt/expectation.json b/tools/wpt/expectation.json
index 0d53dd962ab914..813abbbba562e3 100644
--- a/tools/wpt/expectation.json
+++ b/tools/wpt/expectation.json
@@ -1479,8 +1479,8 @@
         ],
         "is.tentative.any.html": true,
         "is.tentative.any.worker.html": true,
-        "toString.tentative.any.html": false,
-        "toString.tentative.any.worker.html": false,
+        "toString.tentative.any.html": true,
+        "toString.tentative.any.worker.html": true,
         "type.tentative.any.html": false,
         "type.tentative.any.worker.html": false
       },