diff --git a/bench_util/benches/utf8.rs b/bench_util/benches/utf8.rs
index 7a9066d1e0..a8d6e20eb1 100644
--- a/bench_util/benches/utf8.rs
+++ b/bench_util/benches/utf8.rs
@@ -7,12 +7,14 @@ use deno_bench_util::bencher::Bencher;
 use deno_bench_util::BenchOptions;
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 
 fn setup() -> Vec<Extension> {
   vec![Extension::builder("bench_setup")
     .js(vec![ExtensionFileSource {
       specifier: "setup.js".to_string(),
-      code: r#"
+      code: ExtensionFileSourceCode::IncludedInBinary(
+        r#"
       const hello = "hello world\n";
       const hello1k = hello.repeat(1e3);
       const hello1m = hello.repeat(1e6);
@@ -20,6 +22,7 @@ fn setup() -> Vec<Extension> {
       const hello1kEncoded = Deno.core.encode(hello1k);
       const hello1mEncoded = Deno.core.encode(hello1m);
       "#,
+      ),
     }])
     .build()]
 }
diff --git a/cli/build.rs b/cli/build.rs
index 84d8fd5498..807009a5d6 100644
--- a/cli/build.rs
+++ b/cli/build.rs
@@ -4,10 +4,11 @@ use std::env;
 use std::path::Path;
 use std::path::PathBuf;
 
-use deno_core::include_js_files_dir;
+use deno_core::include_js_files;
 use deno_core::snapshot_util::*;
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 use deno_runtime::deno_cache::SqliteBackedCache;
 use deno_runtime::permissions::PermissionsContainer;
 use deno_runtime::*;
@@ -17,7 +18,6 @@ mod ts {
   use crate::deno_webgpu_get_declaration;
   use deno_core::error::custom_error;
   use deno_core::error::AnyError;
-  use deno_core::include_js_files_dir;
   use deno_core::op;
   use deno_core::OpState;
   use deno_runtime::deno_node::SUPPORTED_BUILTIN_NODE_MODULES;
@@ -260,7 +260,7 @@ mod ts {
         op_load::decl(),
         op_script_version::decl(),
       ])
-      .js(include_js_files_dir! {
+      .js(include_js_files! {
         dir "tsc",
         "00_typescript.js",
         "99_main_compiler.js",
@@ -354,13 +354,15 @@ fn create_cli_snapshot(snapshot_path: PathBuf) {
     deno_flash::init::<PermissionsContainer>(false), // No --unstable
   ];
 
-  let mut esm_files = include_js_files_dir!(
+  let mut esm_files = include_js_files!(
     dir "js",
     "40_testing.js",
   );
   esm_files.push(ExtensionFileSource {
     specifier: "runtime/js/99_main.js".to_string(),
-    code: deno_runtime::js::SOURCE_CODE_FOR_99_MAIN_JS,
+    code: ExtensionFileSourceCode::IncludedInBinary(
+      deno_runtime::js::SOURCE_CODE_FOR_99_MAIN_JS,
+    ),
   });
   let extensions_with_js = vec![Extension::builder("cli")
     // FIXME(bartlomieju): information about which extensions were
diff --git a/core/extensions.rs b/core/extensions.rs
index e497b80031..ab686d8682 100644
--- a/core/extensions.rs
+++ b/core/extensions.rs
@@ -6,10 +6,21 @@ use std::rc::Rc;
 use std::task::Context;
 use v8::fast_api::FastFunction;
 
+#[derive(Clone, Debug)]
+pub enum ExtensionFileSourceCode {
+  /// Source code is included in the binary produced. Either by being defined
+  /// inline, or included using `include_str!()`. If you are snapshotting, this
+  /// will result in two copies of the source code being included - one in the
+  /// snapshot, the other the static string in the `Extension`.
+  IncludedInBinary(&'static str),
+  // TODO(bartlomieju): add more variants that allow to read file from the disk,
+  // and not include it in the binary.
+}
+
 #[derive(Clone, Debug)]
 pub struct ExtensionFileSource {
   pub specifier: String,
-  pub code: &'static str,
+  pub code: ExtensionFileSourceCode,
 }
 pub type OpFnRef = v8::FunctionCallback;
 pub type OpMiddlewareFn = dyn Fn(OpDecl) -> OpDecl;
@@ -180,6 +191,9 @@ impl ExtensionBuilder {
 
   pub fn js(&mut self, js_files: Vec<ExtensionFileSource>) -> &mut Self {
     let js_files =
+      // TODO(bartlomieju): if we're automatically remapping here, then we should
+      // use a different result struct that `ExtensionFileSource` as it's confusing
+      // when (and why) the remapping happens.
       js_files.into_iter().map(|file_source| ExtensionFileSource {
         specifier: format!("internal:{}/{}", self.name, file_source.specifier),
         code: file_source.code,
@@ -189,16 +203,15 @@ impl ExtensionBuilder {
   }
 
   pub fn esm(&mut self, esm_files: Vec<ExtensionFileSource>) -> &mut Self {
-    let esm_files =
-      esm_files
-        .into_iter()
-        .map(|file_source| ExtensionFileSource {
-          specifier: format!(
-            "internal:{}/{}",
-            self.name, file_source.specifier
-          ),
-          code: file_source.code,
-        });
+    let esm_files = esm_files
+      .into_iter()
+      // TODO(bartlomieju): if we're automatically remapping here, then we should
+      // use a different result struct that `ExtensionFileSource` as it's confusing
+      // when (and why) the remapping happens.
+      .map(|file_source| ExtensionFileSource {
+        specifier: format!("internal:{}/{}", self.name, file_source.specifier),
+        code: file_source.code,
+      });
     self.esm.extend(esm_files);
     self
   }
@@ -259,48 +272,53 @@ impl ExtensionBuilder {
 }
 
 /// Helps embed JS files in an extension. Returns a vector of
-/// `ExtensionFileSource`, that represent the filename and source code.
+/// `ExtensionFileSource`, that represent the filename and source code. All
+/// specified files are rewritten into "internal:<extension_name>/<file_name>".
 ///
-/// Example:
+/// An optional "dir" option can be specified to prefix all files with a
+/// directory name.
+///
+/// Example (for "my_extension"):
 /// ```ignore
 /// include_js_files!(
 ///   "01_hello.js",
 ///   "02_goodbye.js",
 /// )
-/// ```
-#[macro_export]
-macro_rules! include_js_files {
-  ($($file:literal,)+) => {
-    vec![
-      $($crate::ExtensionFileSource {
-        specifier: $file.to_string(),
-        code: include_str!($file),
-      },)+
-    ]
-  };
-}
-
-/// Helps embed JS files in an extension. Returns a vector of
-/// `ExtensionFileSource`, that represent the filename and source code.
-/// Additional "dir" option is required, that specifies which directory in the
-/// crate root contains the listed files. "dir" option will be prepended to
-/// each file name.
+/// // Produces following specifiers:
+/// - "internal:my_extension/01_hello.js"
+/// - "internal:my_extension/02_goodbye.js"
 ///
-/// Example:
+/// /// Example with "dir" option (for "my_extension"):
 /// ```ignore
-/// include_js_files_dir!(
-///   dir "example",
+/// include_js_files!(
+///   dir "js",
 ///   "01_hello.js",
 ///   "02_goodbye.js",
 /// )
+/// // Produces following specifiers:
+/// - "internal:my_extension/js/01_hello.js"
+/// - "internal:my_extension/js/02_goodbye.js"
 /// ```
 #[macro_export]
-macro_rules! include_js_files_dir {
+macro_rules! include_js_files {
   (dir $dir:literal, $($file:literal,)+) => {
     vec![
       $($crate::ExtensionFileSource {
         specifier: concat!($dir, "/", $file).to_string(),
-        code: include_str!(concat!($dir, "/", $file)),
+        code: $crate::ExtensionFileSourceCode::IncludedInBinary(
+          include_str!(concat!($dir, "/", $file)
+        )),
+      },)+
+    ]
+  };
+
+  ($($file:literal,)+) => {
+    vec![
+      $($crate::ExtensionFileSource {
+        specifier: $file.to_string(),
+        code: $crate::ExtensionFileSourceCode::IncludedInBinary(
+          include_str!($file)
+        ),
       },)+
     ]
   };
diff --git a/core/lib.rs b/core/lib.rs
index a777013399..51a03493d6 100644
--- a/core/lib.rs
+++ b/core/lib.rs
@@ -55,6 +55,7 @@ pub use crate::async_cell::RcRef;
 pub use crate::extensions::Extension;
 pub use crate::extensions::ExtensionBuilder;
 pub use crate::extensions::ExtensionFileSource;
+pub use crate::extensions::ExtensionFileSourceCode;
 pub use crate::extensions::OpDecl;
 pub use crate::extensions::OpMiddlewareFn;
 pub use crate::flags::v8_set_flags;
diff --git a/core/modules.rs b/core/modules.rs
index 1f427508a1..43dabf4112 100644
--- a/core/modules.rs
+++ b/core/modules.rs
@@ -3,6 +3,7 @@
 use crate::bindings;
 use crate::error::generic_error;
 use crate::extensions::ExtensionFileSource;
+use crate::extensions::ExtensionFileSourceCode;
 use crate::module_specifier::ModuleSpecifier;
 use crate::resolve_import;
 use crate::resolve_url;
@@ -402,7 +403,11 @@ impl ModuleLoader for InternalModuleLoader {
       let result = if let Some(load_callback) = &self.maybe_load_callback {
         load_callback(file_source)
       } else {
-        Ok(file_source.code.to_string())
+        match file_source.code {
+          ExtensionFileSourceCode::IncludedInBinary(code) => {
+            Ok(code.to_string())
+          }
+        }
       };
 
       return async move {
diff --git a/core/runtime.rs b/core/runtime.rs
index 25a09e85e7..ae2b0489b1 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -21,6 +21,7 @@ use crate::source_map::SourceMapCache;
 use crate::source_map::SourceMapGetter;
 use crate::Extension;
 use crate::ExtensionFileSource;
+use crate::ExtensionFileSourceCode;
 use crate::NoopModuleLoader;
 use crate::OpMiddlewareFn;
 use crate::OpResult;
@@ -868,11 +869,14 @@ impl JsRuntime {
       {
         let js_files = ext.get_js_sources();
         for file_source in js_files {
+          let ExtensionFileSourceCode::IncludedInBinary(code) =
+            file_source.code;
+
           // TODO(@AaronO): use JsRuntime::execute_static() here to move src off heap
           realm.execute_script(
             self.v8_isolate(),
             &file_source.specifier,
-            file_source.code,
+            code,
           )?;
         }
       }
diff --git a/ext/node/lib.rs b/ext/node/lib.rs
index 43861ef46f..697100c8fe 100644
--- a/ext/node/lib.rs
+++ b/ext/node/lib.rs
@@ -2,7 +2,6 @@
 
 use deno_core::error::AnyError;
 use deno_core::include_js_files;
-use deno_core::include_js_files_dir;
 use deno_core::located_script_name;
 use deno_core::op;
 use deno_core::Extension;
@@ -96,7 +95,7 @@ fn op_node_build_os() -> String {
 }
 
 pub fn init_polyfill() -> Extension {
-  let esm_files = include_js_files_dir!(
+  let esm_files = include_js_files!(
     dir "polyfills",
     "_core.ts",
     "_crypto/crypto_browserify/asn1.js/base/buffer.js",
diff --git a/ext/url/benches/url_ops.rs b/ext/url/benches/url_ops.rs
index 001b5de926..828b022978 100644
--- a/ext/url/benches/url_ops.rs
+++ b/ext/url/benches/url_ops.rs
@@ -7,6 +7,7 @@ use deno_bench_util::bencher::Bencher;
 
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 
 fn setup() -> Vec<Extension> {
   vec![
@@ -15,9 +16,11 @@ fn setup() -> Vec<Extension> {
     Extension::builder("bench_setup")
       .esm(vec![ExtensionFileSource {
         specifier: "internal:setup".to_string(),
-        code: r#"import { URL } from "internal:deno_url/00_url.js";
+        code: ExtensionFileSourceCode::IncludedInBinary(
+          r#"import { URL } from "internal:deno_url/00_url.js";
         globalThis.URL = URL;
         "#,
+        ),
       }])
       .build(),
   ]
diff --git a/ext/web/benches/encoding.rs b/ext/web/benches/encoding.rs
index bb297a1bfe..bfae079371 100644
--- a/ext/web/benches/encoding.rs
+++ b/ext/web/benches/encoding.rs
@@ -6,6 +6,7 @@ use deno_bench_util::bencher::benchmark_group;
 use deno_bench_util::bencher::Bencher;
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 use deno_web::BlobStore;
 
 struct Permissions;
@@ -32,11 +33,13 @@ fn setup() -> Vec<Extension> {
     Extension::builder("bench_setup")
       .esm(vec![ExtensionFileSource {
         specifier: "internal:setup".to_string(),
-        code: r#"
+        code: ExtensionFileSourceCode::IncludedInBinary(
+          r#"
         import { TextDecoder } from "internal:deno_web/08_text_encoding.js";
         globalThis.TextDecoder = TextDecoder;
         globalThis.hello12k = Deno.core.encode("hello world\n".repeat(1e3));
         "#,
+        ),
       }])
       .state(|state| {
         state.put(Permissions {});
diff --git a/ext/web/benches/timers_ops.rs b/ext/web/benches/timers_ops.rs
index f01b4c5323..657082df4b 100644
--- a/ext/web/benches/timers_ops.rs
+++ b/ext/web/benches/timers_ops.rs
@@ -6,6 +6,7 @@ use deno_bench_util::bencher::benchmark_group;
 use deno_bench_util::bencher::Bencher;
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 use deno_web::BlobStore;
 
 struct Permissions;
@@ -32,11 +33,11 @@ fn setup() -> Vec<Extension> {
     .esm(vec![
       ExtensionFileSource {
         specifier: "internal:setup".to_string(), 
-        code: r#"
+        code: ExtensionFileSourceCode::IncludedInBinary(r#"
       import { setTimeout, handleTimerMacrotask } from "internal:deno_web/02_timers.js";
       globalThis.setTimeout = setTimeout;
       Deno.core.setMacrotaskCallback(handleTimerMacrotask);
-      "#
+      "#)
       },
     ])
     .state(|state| {
diff --git a/ext/webidl/benches/dict.rs b/ext/webidl/benches/dict.rs
index 00bef49350..df0844fce2 100644
--- a/ext/webidl/benches/dict.rs
+++ b/ext/webidl/benches/dict.rs
@@ -7,6 +7,7 @@ use deno_bench_util::bencher::Bencher;
 
 use deno_core::Extension;
 use deno_core::ExtensionFileSource;
+use deno_core::ExtensionFileSourceCode;
 
 fn setup() -> Vec<Extension> {
   vec![
@@ -14,7 +15,9 @@ fn setup() -> Vec<Extension> {
     Extension::builder("deno_webidl_bench")
       .esm(vec![ExtensionFileSource {
         specifier: "internal:setup".to_string(),
-        code: include_str!("dict.js"),
+        code: ExtensionFileSourceCode::IncludedInBinary(include_str!(
+          "dict.js"
+        )),
       }])
       .build(),
   ]
diff --git a/runtime/build.rs b/runtime/build.rs
index bbdec8f57e..a813d63cb4 100644
--- a/runtime/build.rs
+++ b/runtime/build.rs
@@ -1,6 +1,6 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 
-use deno_core::include_js_files_dir;
+use deno_core::include_js_files;
 use std::env;
 use std::path::PathBuf;
 
@@ -18,6 +18,7 @@ mod not_docs {
   use deno_ast::SourceTextInfo;
   use deno_core::error::AnyError;
   use deno_core::ExtensionFileSource;
+  use deno_core::ExtensionFileSourceCode;
 
   fn transpile_ts_for_snapshotting(
     file_source: &ExtensionFileSource,
@@ -34,13 +35,15 @@ mod not_docs {
       ),
     };
 
+    let ExtensionFileSourceCode::IncludedInBinary(code) = file_source.code;
+
     if !should_transpile {
-      return Ok(file_source.code.to_string());
+      return Ok(code.to_string());
     }
 
     let parsed = deno_ast::parse_module(ParseParams {
       specifier: file_source.specifier.to_string(),
-      text_info: SourceTextInfo::from_string(file_source.code.to_string()),
+      text_info: SourceTextInfo::from_string(code.to_string()),
       media_type,
       capture_tokens: false,
       scope_analysis: false,
@@ -188,7 +191,7 @@ mod not_docs {
         "deno_http",
         "deno_flash",
       ])
-      .esm(include_js_files_dir!(
+      .esm(include_js_files!(
         dir "js",
         "01_build.js",
         "01_errors.js",
@@ -283,7 +286,9 @@ mod not_docs {
           .dependencies(vec!["runtime"])
           .esm(vec![ExtensionFileSource {
             specifier: "js/99_main.js".to_string(),
-            code: include_str!("js/99_main.js"),
+            code: ExtensionFileSourceCode::IncludedInBinary(include_str!(
+              "js/99_main.js"
+            )),
           }])
           .build(),
       );