diff --git a/.cargo/config.toml b/.cargo/config.toml
index 8317a149..5c9afebe 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -4,7 +4,7 @@
 # https://doc.rust-lang.org/cargo/reference/config.html
 # Disable reference-types since Wizer (as of version 7.0.0) does not support
 # reference-types.
-[target.wasm32-wasi]
+[target.wasm32-wasip1]
 rustflags = [
     "-C",
     "target-feature=+simd128",
diff --git a/.github/workflows/build-assets.yml b/.github/workflows/build-assets.yml
index a9004836..eea28d62 100644
--- a/.github/workflows/build-assets.yml
+++ b/.github/workflows/build-assets.yml
@@ -40,18 +40,18 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: engine
-          path: target/wasm32-wasi/release/javy_core.wasm
+          path: target/wasm32-wasip1/release/javy_core.wasm
 
       - name: Upload quickjs_provider to artifacts
         uses: actions/upload-artifact@v4
         with:
           name: provider
-          path: target/wasm32-wasi/release/javy_quickjs_provider.wasm
+          path: target/wasm32-wasip1/release/javy_quickjs_provider.wasm
 
       - name: Wizen and archive wizened quickjs_provider
         run: |
-          wizer target/wasm32-wasi/release/javy_quickjs_provider.wasm --allow-wasi --init-func initialize_runtime --wasm-bulk-memory true -o target/wasm32-wasi/release/javy_quickjs_provider_wizened.wasm
-          gzip -k -f target/wasm32-wasi/release/javy_quickjs_provider_wizened.wasm && mv target/wasm32-wasi/release/javy_quickjs_provider_wizened.wasm.gz javy-quickjs_provider.wasm.gz
+          wizer target/wasm32-wasip1/release/javy_quickjs_provider.wasm --allow-wasi --init-func initialize_runtime --wasm-bulk-memory true -o target/wasm32-wasip1/release/javy_quickjs_provider_wizened.wasm
+          gzip -k -f target/wasm32-wasip1/release/javy_quickjs_provider_wizened.wasm && mv target/wasm32-wasip1/release/javy_quickjs_provider_wizened.wasm.gz javy-quickjs_provider.wasm.gz
 
       - name: Upload archived quickjs_provider to artifacts
         uses: actions/upload-artifact@v4
@@ -133,12 +133,12 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           name: engine
-          path: target/wasm32-wasi/release/
+          path: target/wasm32-wasip1/release/
 
       - uses: actions/download-artifact@v4
         with:
           name: provider
-          path: target/wasm32-wasi/release/
+          path: target/wasm32-wasip1/release/
 
       - name: Build CLI ${{ matrix.os }}
         run: cargo build --release --target ${{ matrix.target }} --package javy-cli
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9d510228..42b25191 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,19 +24,16 @@ jobs:
         with:
           os: macos
 
-      - name: Install cargo-wasi
-        run: cargo install cargo-wasi
-
       - name: Install cargo-hack
         uses: taiki-e/install-action@cargo-hack
 
       - name: Compile core
-        run: cargo build -p javy-core --release --target=wasm32-wasi
+        run: cargo build -p javy-core --release --target=wasm32-wasip1
 
       - name: Test
-        env: 
-          CARGO_TARGET_WASM32_WASI_RUNNER: wasmtime --dir=.
-        run: cargo hack wasi test --workspace --exclude=javy-cli --exclude=javy-config --exclude=javy-runner --each-feature -- --nocapture
+        env:
+          CARGO_TARGET_WASM32_WASIP1_RUNNER: wasmtime --dir=.
+        run: cargo hack test --target=wasm32-wasip1 --workspace --exclude=javy-cli --exclude=javy-config --exclude=javy-runner --each-feature -- --nocapture
 
       - name: Test Config
         run: cargo test --package=javy-config
@@ -50,10 +47,10 @@ jobs:
           --exclude=javy-cli \
           --exclude=javy-runner \
           --exclude=javy-fuzz \
-          --target=wasm32-wasi --all-targets -- -D warnings
-        
-      # We need to specify a different job for linting `javy-runner` given that 
-      # it depends on Wasmtime and Cranelift cannot be compiled to `wasm32-wasi`
+          --target=wasm32-wasip1 --all-targets -- -D warnings
+
+      # We need to specify a different job for linting `javy-runner` given that
+      # it depends on Wasmtime and Cranelift cannot be compiled to `wasm32-wasip1`
       - name: Lint Runner
         run: cargo clippy --package=javy-runner -- -D warnings
 
@@ -61,13 +58,13 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: engine
-          path: target/wasm32-wasi/release/javy_core.wasm
+          path: target/wasm32-wasip1/release/javy_core.wasm
 
       - name: Upload quickjs_provider to artifacts
         uses: actions/upload-artifact@v4
         with:
           name: provider
-          path: target/wasm32-wasi/release/javy_quickjs_provider.wasm
+          path: target/wasm32-wasip1/release/javy_quickjs_provider.wasm
 
   cli:
     name: test_cli
@@ -83,12 +80,12 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           name: engine
-          path: target/wasm32-wasi/release/
+          path: target/wasm32-wasip1/release/
 
       - uses: actions/download-artifact@v4
         with:
           name: provider
-          path: target/wasm32-wasi/release/
+          path: target/wasm32-wasip1/release/
 
       - name: Test CLI
         run: CARGO_PROFILE_RELEASE_LTO=off cargo test --package=javy-cli --release -- --nocapture
diff --git a/.github/workflows/cli-features.yml b/.github/workflows/cli-features.yml
index 9c8cfe27..6fedddc1 100644
--- a/.github/workflows/cli-features.yml
+++ b/.github/workflows/cli-features.yml
@@ -19,5 +19,5 @@ jobs:
 
       - name: Test `experimental_event_loop`
         run: |
-          cargo build --package=javy-core --target=wasm32-wasi --release --features=experimental_event_loop
+          cargo build --package=javy-core --target=wasm32-wasip1 --release --features=experimental_event_loop
           cargo test --package=javy-cli --features=experimental_event_loop --release -- --nocapture
diff --git a/.github/workflows/wpt.yml b/.github/workflows/wpt.yml
index 7bf1821d..587f2bac 100644
--- a/.github/workflows/wpt.yml
+++ b/.github/workflows/wpt.yml
@@ -21,7 +21,7 @@ jobs:
 
       - name: WPT
         run: |
-          cargo build --package=javy-core --release --target=wasm32-wasi --features=experimental_event_loop
+          cargo build --package=javy-core --release --target=wasm32-wasip1 --features=experimental_event_loop
           CARGO_PROFILE_RELEASE_LTO=off cargo build --package=javy-cli --release
           npm install --prefix wpt
           npm test --prefix wpt
diff --git a/Makefile b/Makefile
index 6d12916c..001e2ff1 100644
--- a/Makefile
+++ b/Makefile
@@ -15,17 +15,17 @@ cli: core
 	CARGO_PROFILE_RELEASE_LTO=off cargo build --package=javy-cli --release
 
 core:
-	cargo build --package=javy-core --release --target=wasm32-wasi --features=$(CORE_FEATURES)
+	cargo build --package=javy-core --release --target=wasm32-wasip1 --features=$(CORE_FEATURES)
 
 docs:
 	cargo doc --package=javy-cli --open
-	cargo doc --package=javy-core --open --target=wasm32-wasi
+	cargo doc --package=javy-core --open --target=wasm32-wasip1
 
 test-javy:
-	CARGO_TARGET_WASM32_WASI_RUNNER="wasmtime --dir=."  cargo wasi test --package=javy --features json,messagepack -- --nocapture
+	CARGO_TARGET_WASM32_WASIP1_RUNNER="wasmtime --dir=." cargo test --package=javy --target=wasm32-wasip1 --features json,messagepack -- --nocapture
 
 test-core:
-	cargo wasi test --package=javy-core -- --nocapture
+	CARGO_TARGET_WASM32_WASIP1_RUNNER="wasmtime" cargo test --package=javy-core --target=wasm32-wasip1 -- --nocapture
 
 # Test in release mode to skip some debug assertions
 # Note: to make this faster, the engine should be optimized beforehand (wasm-strip + wasm-opt).
@@ -53,11 +53,11 @@ fmt: fmt-javy fmt-core fmt-cli
 
 fmt-javy:
 	cargo fmt --package=javy -- --check
-	cargo clippy --package=javy --target=wasm32-wasi --all-targets -- -D warnings
+	cargo clippy --package=javy --target=wasm32-wasip1 --all-targets -- -D warnings
 
 fmt-core:
 	cargo fmt --package=javy-core -- --check
-	cargo clippy --package=javy-core --target=wasm32-wasi --all-targets -- -D warnings
+	cargo clippy --package=javy-core --target=wasm32-wasip1 --all-targets -- -D warnings
 
 # Use `--release` on CLI clippy to align with `test-cli`.
 # This reduces the size of the target directory which improves CI stability.
diff --git a/crates/cli/benches/benchmark.rs b/crates/cli/benches/benchmark.rs
index 9f62928a..aca1085b 100644
--- a/crates/cli/benches/benchmark.rs
+++ b/crates/cli/benches/benchmark.rs
@@ -121,7 +121,7 @@ impl FunctionCase {
             let qjs_provider = Module::new(
                 &self.engine,
                 fs::read(Path::new(
-                    "../../target/wasm32-wasi/release/javy_quickjs_provider_wizened.wasm",
+                    "../../target/wasm32-wasip1/release/javy_quickjs_provider_wizened.wasm",
                 ))?,
             )?;
             let instance = linker.instantiate(store.as_context_mut(), &qjs_provider)?;
diff --git a/crates/cli/build.rs b/crates/cli/build.rs
index 4ebe2a2c..beca6db2 100644
--- a/crates/cli/build.rs
+++ b/crates/cli/build.rs
@@ -48,7 +48,7 @@ fn copy_javy_core() -> Result<()> {
         .unwrap()
         .parent()
         .unwrap()
-        .join("target/wasm32-wasi/release");
+        .join("target/wasm32-wasip1/release");
     let engine_path = module_path.join("javy_core.wasm");
     let quickjs_provider_path = module_path.join("javy_quickjs_provider.wasm");
     let quickjs_provider_wizened_path = module_path.join("javy_quickjs_provider_wizened.wasm");
diff --git a/crates/cli/tests/dylib_test.rs b/crates/cli/tests/dylib_test.rs
index 7fb0415c..05031a25 100644
--- a/crates/cli/tests/dylib_test.rs
+++ b/crates/cli/tests/dylib_test.rs
@@ -65,7 +65,7 @@ fn provider_module() -> Result<Vec<u8>> {
     lib_path.pop();
     lib_path = lib_path.join(
         Path::new("target")
-            .join("wasm32-wasi")
+            .join("wasm32-wasip1")
             .join("release")
             .join("javy_quickjs_provider_wizened.wasm"),
     );
diff --git a/crates/javy/publish.sh b/crates/javy/publish.sh
index 1701b9f6..ecb5ce17 100755
--- a/crates/javy/publish.sh
+++ b/crates/javy/publish.sh
@@ -2,4 +2,4 @@
 
 set -e
 
-cargo publish --target=wasm32-wasi
+cargo publish --target=wasm32-wasip1
diff --git a/crates/javy/tests/262.rs b/crates/javy/tests/262.rs
index f09e462f..51040730 100644
--- a/crates/javy/tests/262.rs
+++ b/crates/javy/tests/262.rs
@@ -1,2 +1,2 @@
 #[cfg(feature = "json")]
-javy_test_macros::t262!(path = "crates/javy/test262");
+javy_test_macros::t262!(path = "./test262");
diff --git a/crates/test-macros/src/lib.rs b/crates/test-macros/src/lib.rs
index d4bed847..426bad5c 100644
--- a/crates/test-macros/src/lib.rs
+++ b/crates/test-macros/src/lib.rs
@@ -14,7 +14,7 @@ use anyhow::bail;
 use proc_macro::TokenStream;
 use proc_macro2::Span;
 use quote::quote;
-use std::path::{Path, PathBuf};
+use std::{env, path::PathBuf};
 use syn::{meta::ParseNestedMeta, parse_macro_input, Ident, LitBool, LitStr, Result, ReturnType};
 
 struct Config262 {
@@ -23,8 +23,10 @@ struct Config262 {
 
 impl Config262 {
     fn validate(&self) -> anyhow::Result<()> {
-        let path: Box<Path> = self.root.clone().into();
-        if path.is_dir() {
+        if PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap())
+            .join(&self.root)
+            .is_dir()
+        {
             Ok(())
         } else {
             bail!("Invalid path")
@@ -116,10 +118,13 @@ fn gen_tests(
     harness_str: &String,
     prefix: &'static str,
 ) -> proc_macro2::TokenStream {
-    let parse_dir = std::fs::read_dir(dir).expect("parse directory to be available");
+    let package_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+    let parse_dir =
+        std::fs::read_dir(package_path.join(dir)).expect("parse directory to be available");
     let spec = parse_dir.filter_map(|e| e.ok()).map(move |entry| {
             let path = entry.path();
-            let path_str = path.clone().into_os_string().into_string().unwrap();
+            let path = path.strip_prefix(&package_path).unwrap();
+            let path_str = path.to_str().unwrap();
             let name = path.file_stem().unwrap().to_str().unwrap();
             let name = name.replace('.', "_");
             let name = name.replace('-', "_");
@@ -299,7 +304,7 @@ fn expand_cli_tests(test_config: &CliTestConfig, func: syn::ItemFn) -> Result<To
                     root.pop();
                     root = root.join(
                         std::path::Path::new("target")
-                            .join("wasm32-wasi")
+                            .join("wasm32-wasip1")
                             .join("release")
                             .join("javy_quickjs_provider_wizened.wasm"),
                     );
diff --git a/docs/docs-contributing-architecture.md b/docs/docs-contributing-architecture.md
index 57d05ab5..e162d174 100644
--- a/docs/docs-contributing-architecture.md
+++ b/docs/docs-contributing-architecture.md
@@ -18,7 +18,7 @@ We anticipate most changes will be to the `javy-cli` and `javy` crates.
 ### `javy`
 
 The entrypoint for working with Javy as a library for third parties. This crate
-is intended to compile to `wasm32-wasi` and provide ergonomic APIs for
+is intended to compile to `wasm32-wasip1` and provide ergonomic APIs for
 configuring a QuickJS-based runtime. If there is a configuration option for
 QuickJS that would be helpful, this is the place to add it.
 
diff --git a/docs/docs-contributing-building.md b/docs/docs-contributing-building.md
index a1dde2e3..e832630f 100644
--- a/docs/docs-contributing-building.md
+++ b/docs/docs-contributing-building.md
@@ -3,7 +3,7 @@
 - On Ubuntu, `sudo apt-get install curl pkg-config libssl-dev clang`
 - [rustup](https://rustup.rs/)
 - Stable Rust, installed via `rustup install stable && rustup default stable`
-- wasm32-wasi, can be installed via `rustup target add wasm32-wasi`
+- wasm32-wasip1, can be installed via `rustup target add wasm32-wasip1`
 - cmake, depending on your operating system and architecture, it might not be
   installed by default. On MacOS it can be installed with `homebrew` via `brew
   install cmake`. On Ubuntu, `sudo apt-get install cmake`.
@@ -15,14 +15,14 @@
 In the repository root, run:
 
 ```
-$ cargo build -p javy-core --target=wasm32-wasi -r
+$ cargo build -p javy-core --target=wasm32-wasip1 -r
 $ cargo build -p javy-cli -r
 ```
 
 Alternatively if you want to install the `javy` binary globally, at the
 repository root, run:
 ```
-$ cargo build -p javy-core --target=wasm32-wasi -r
+$ cargo build -p javy-core --target=wasm32-wasip1 -r
 $ cargo install --path crates/cli
 ```
 
diff --git a/docs/docs-contributing-developing.md b/docs/docs-contributing-developing.md
index ca0288bc..efc5a333 100644
--- a/docs/docs-contributing-developing.md
+++ b/docs/docs-contributing-developing.md
@@ -1,6 +1,4 @@
 # Development requirements
 
-- `wasmtime-cli`, can be installed via `cargo install wasmtime-cli` (required for
-  `cargo-wasi`)
-- `cargo-wasi`, can be installed via `cargo install cargo-wasi`
+- `wasmtime-cli`, can be installed via `cargo install wasmtime-cli`
 - `cargo-hack`, can be installed via `cargo +stable install cargo-hack --locked`
diff --git a/docs/docs-contributing-testing-locally.md b/docs/docs-contributing-testing-locally.md
index 08eef7dc..001a2c56 100644
--- a/docs/docs-contributing-testing-locally.md
+++ b/docs/docs-contributing-testing-locally.md
@@ -15,5 +15,5 @@ cargo +stable install cargo-hack --locked
 
 3. Run tests, eg:
 ```
-CARGO_TARGET_WASM32_WASI_RUNNER="wasmtime --dir=." cargo hack wasi test --workspace --exclude=javy-cli --exclude=javy-config --each-feature -- --nocapture
+CARGO_TARGET_WASM32_WASIP1_RUNNER="wasmtime --dir=." cargo hack test --target=wasm32-wasip1 --workspace --exclude=javy-cli --exclude=javy-config --each-feature -- --nocapture
 ```
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index f6549643..24d9835f 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,5 +1,5 @@
 [toolchain]
 channel = "stable"
 components = ["clippy", "rustfmt"]
-targets = ["wasm32-wasi"]
+targets = ["wasm32-wasip1"]
 profile = "default"