diff --git a/bench_util/benches/utf8.rs b/bench_util/benches/utf8.rs
index 021c409b86..499571e5e6 100644
--- a/bench_util/benches/utf8.rs
+++ b/bench_util/benches/utf8.rs
@@ -9,19 +9,14 @@ fn setup() -> Vec<Extension> {
   vec![Extension::builder()
     .js(vec![(
       "setup.js",
-      Box::new(|| {
-        Ok(
-          r#"
+      r#"
       const hello = "hello world\n";
       const hello1k = hello.repeat(1e3);
       const hello1m = hello.repeat(1e6);
       const helloEncoded = Deno.core.encode(hello);
       const hello1kEncoded = Deno.core.encode(hello1k);
       const hello1mEncoded = Deno.core.encode(hello1m);
-      "#
-          .into(),
-        )
-      }),
+      "#,
     )])
     .build()]
 }
diff --git a/core/extensions.rs b/core/extensions.rs
index 6dd2270fc2..6829871242 100644
--- a/core/extensions.rs
+++ b/core/extensions.rs
@@ -3,8 +3,7 @@ use crate::OpState;
 use anyhow::Error;
 use std::task::Context;
 
-pub type SourcePair = (&'static str, Box<SourceLoadFn>);
-pub type SourceLoadFn = dyn Fn() -> Result<String, Error>;
+pub type SourcePair = (&'static str, &'static str);
 pub type OpFnRef = v8::FunctionCallback;
 pub type OpMiddlewareFn = dyn Fn(OpDecl) -> OpDecl;
 pub type OpStateFn = dyn Fn(&mut OpState) -> Result<(), Error>;
@@ -169,9 +168,8 @@ impl ExtensionBuilder {
     }
   }
 }
-/// Helps embed JS files in an extension. Returns Vec<(&'static str, Box<SourceLoadFn>)>
-/// representing the filename and source code. This is only meant for extensions
-/// that will be snapshotted, as code will be loaded at runtime.
+/// Helps embed JS files in an extension. Returns Vec<(&'static str, &'static str)>
+/// representing the filename and source code.
 ///
 /// Example:
 /// ```ignore
@@ -187,13 +185,7 @@ macro_rules! include_js_files {
     vec![
       $((
         concat!($prefix, "/", $file),
-        Box::new(|| {
-          let c = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
-          let path = c.join($file);
-          println!("cargo:rerun-if-changed={}", path.display());
-          let src = std::fs::read_to_string(path)?;
-          Ok(src)
-        }),
+        include_str!($file),
       ),)+
     ]
   };
diff --git a/core/runtime.rs b/core/runtime.rs
index f589ad25b8..f8afeb76c5 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -491,9 +491,8 @@ impl JsRuntime {
     for m in extensions.iter_mut() {
       let js_files = m.init_js();
       for (filename, source) in js_files {
-        let source = source()?;
         // TODO(@AaronO): use JsRuntime::execute_static() here to move src off heap
-        realm.execute_script(self, filename, &source)?;
+        realm.execute_script(self, filename, source)?;
       }
     }
     // Restore extensions
diff --git a/ext/url/benches/url_ops.rs b/ext/url/benches/url_ops.rs
index ed27b6f80d..315ea72606 100644
--- a/ext/url/benches/url_ops.rs
+++ b/ext/url/benches/url_ops.rs
@@ -11,9 +11,7 @@ fn setup() -> Vec<Extension> {
     Extension::builder()
       .js(vec![(
         "setup",
-        Box::new(|| {
-          Ok(r#"const { URL } = globalThis.__bootstrap.url;"#.to_owned())
-        }),
+        "const { URL } = globalThis.__bootstrap.url;",
       )])
       .build(),
   ]
diff --git a/ext/web/benches/timers_ops.rs b/ext/web/benches/timers_ops.rs
index 30f50b7d91..f5d03d6c3f 100644
--- a/ext/web/benches/timers_ops.rs
+++ b/ext/web/benches/timers_ops.rs
@@ -26,12 +26,10 @@ fn setup() -> Vec<Extension> {
     deno_web::init::<Permissions>(BlobStore::default(), None),
     Extension::builder()
     .js(vec![
-      ("setup",
-        Box::new(|| Ok(r#"
-        const { opNow, setTimeout, handleTimerMacrotask } = globalThis.__bootstrap.timers;
-        Deno.core.setMacrotaskCallback(handleTimerMacrotask);
-        "#.to_owned())),
-      ),
+      ("setup", r#"
+      const { opNow, setTimeout, handleTimerMacrotask } = globalThis.__bootstrap.timers;
+      Deno.core.setMacrotaskCallback(handleTimerMacrotask);
+      "#),
     ])
     .state(|state| {
       state.put(Permissions{});
diff --git a/ext/webgpu/01_webgpu.js b/ext/webgpu/src/01_webgpu.js
similarity index 100%
rename from ext/webgpu/01_webgpu.js
rename to ext/webgpu/src/01_webgpu.js
diff --git a/ext/webgpu/02_idl_types.js b/ext/webgpu/src/02_idl_types.js
similarity index 100%
rename from ext/webgpu/02_idl_types.js
rename to ext/webgpu/src/02_idl_types.js