diff --git a/global.d.ts b/global.d.ts
index e8970504b..05a292826 100644
--- a/global.d.ts
+++ b/global.d.ts
@@ -1,5 +1,3 @@
-declare const SERVICE_WORKER_CHECKSUM: string
-
 declare module '@bundled-es-modules/cookie' {
   export * as default from 'cookie'
 }
diff --git a/src/_t_sconfig.json b/src/_t_sconfig.json
deleted file mode 100644
index 6d1fb7c49..000000000
--- a/src/_t_sconfig.json
+++ /dev/null
@@ -1,12 +0,0 @@
-{
-  "compilerOptions": {
-    "composite": true,
-    "baseUrl": ".",
-    "paths": {
-      "~/core": ["./core"],
-      "~/core/*": ["./core/*"]
-    }
-  },
-  "include": ["./**/*.ts"],
-  "exclude": ["**/*.test.ts"]
-}
diff --git a/src/browser/global.browser.d.ts b/src/browser/global.browser.d.ts
new file mode 100644
index 000000000..8976bba1f
--- /dev/null
+++ b/src/browser/global.browser.d.ts
@@ -0,0 +1 @@
+declare const SERVICE_WORKER_CHECKSUM: string
diff --git a/src/browser/tsconfig.browser.build.json b/src/browser/tsconfig.browser.build.json
new file mode 100644
index 000000000..8887b4565
--- /dev/null
+++ b/src/browser/tsconfig.browser.build.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.browser.json",
+  "compilerOptions": {
+    "composite": false
+  }
+}
diff --git a/src/browser/tsconfig.browser.json b/src/browser/tsconfig.browser.json
index ae34d1363..0bfc7dd8b 100644
--- a/src/browser/tsconfig.browser.json
+++ b/src/browser/tsconfig.browser.json
@@ -1,8 +1,9 @@
 {
-  "extends": "../../tsconfig.src.json",
+  "extends": "../tsconfig.src.json",
   "compilerOptions": {
+    // Expose browser-specific libraries only for the
+    // source code under the "src/browser" directory.
     "lib": ["DOM", "WebWorker"]
   },
-  "include": ["./**/*.ts"],
-  "exclude": ["**/*.test.ts"]
+  "include": ["./global.browser.d.ts", "./**/*.ts"]
 }
diff --git a/src/core/http.spec.ts b/src/core/http.test.ts
similarity index 100%
rename from src/core/http.spec.ts
rename to src/core/http.test.ts
diff --git a/src/tsconfig.core.build.json b/src/tsconfig.core.build.json
new file mode 100644
index 000000000..0852a1d01
--- /dev/null
+++ b/src/tsconfig.core.build.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.src.json",
+  "compilerOptions": {
+    "composite": false
+  }
+}
diff --git a/src/tsconfig.node.build.json b/src/tsconfig.node.build.json
new file mode 100644
index 000000000..db4cc04cd
--- /dev/null
+++ b/src/tsconfig.node.build.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.node.json",
+  "compilerOptions": {
+    "composite": false
+  }
+}
diff --git a/src/tsconfig.node.json b/src/tsconfig.node.json
index a805dcb5f..c98a860ae 100644
--- a/src/tsconfig.node.json
+++ b/src/tsconfig.node.json
@@ -1,5 +1,5 @@
 {
-  "extends": "../tsconfig.src.json",
+  "extends": "./tsconfig.src.json",
   "compilerOptions": {
     "types": ["node"]
   },
diff --git a/tsconfig.src.json b/src/tsconfig.src.json
similarity index 60%
rename from tsconfig.src.json
rename to src/tsconfig.src.json
index 3dc433e12..1399d3535 100644
--- a/tsconfig.src.json
+++ b/src/tsconfig.src.json
@@ -1,15 +1,15 @@
 {
   // Common configuration for everything
   // living in the "src" directory.
-  "extends": "./tsconfig.base.json",
+  "extends": "../tsconfig.base.json",
   "compilerOptions": {
     "composite": true,
-    "baseUrl": "src",
+    "baseUrl": "./",
     "paths": {
       "~/core": ["core"],
       "~/core/*": ["core/*"]
     }
   },
-  "include": ["src"],
-  "exclude": ["**/*.test.ts"]
+  "include": ["../global.d.ts", "./**/*.ts"],
+  "exclude": ["./**/*.test.ts"]
 }
diff --git a/tsconfig.base.json b/tsconfig.base.json
index e7284865d..bb6721e63 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -1,11 +1,13 @@
 {
   "compilerOptions": {
-    "strict": true,
-    "strictNullChecks": true,
     "target": "es6",
     "module": "esnext",
-    "moduleResolution": "node"
+    "moduleResolution": "node",
+    "strict": true,
+    "strictNullChecks": true,
+    "skipLibCheck": true,
+    "allowSyntheticDefaultImports": false
   },
-  "include": ["global.d.ts"],
+  "include": ["./global.d.ts"],
   "exclude": ["node_modules", "lib"]
 }
diff --git a/tsconfig.test.unit.json b/tsconfig.test.unit.json
index 404dda25d..abea30c95 100644
--- a/tsconfig.test.unit.json
+++ b/tsconfig.test.unit.json
@@ -1,4 +1,6 @@
 {
+  // Configuration for the unit tests living
+  // next to the source code.
   "extends": "./tsconfig.base.json",
   "compilerOptions": {
     "composite": true,
@@ -9,7 +11,7 @@
   "include": ["./src/**/*.test.ts", "./test/support"],
   "references": [
     {
-      "path": "./tsconfig.src.json"
+      "path": "./src/tsconfig.src.json"
     }
   ]
 }
diff --git a/tsup.config.ts b/tsup.config.ts
index 609045a35..3e3807145 100644
--- a/tsup.config.ts
+++ b/tsup.config.ts
@@ -1,3 +1,4 @@
+import * as path from 'node:path'
 import { defineConfig, Options } from 'tsup'
 import * as glob from 'glob'
 import {
@@ -29,6 +30,7 @@ const coreConfig: Options = {
   bundle: false,
   splitting: false,
   dts: true,
+  tsconfig: path.resolve(__dirname, 'src/tsconfig.core.build.json'),
   esbuildPlugins: [forceEsmExtensionsPlugin()],
 }
 
@@ -44,7 +46,7 @@ const nodeConfig: Options = {
   bundle: true,
   splitting: false,
   dts: true,
-
+  tsconfig: path.resolve(__dirname, 'src/tsconfig.node.build.json'),
   esbuildPlugins: [resolveCoreImportsPlugin(), forceEsmExtensionsPlugin()],
 }
 
@@ -58,6 +60,12 @@ const browserConfig: Options = {
   bundle: true,
   splitting: false,
   dts: true,
+  /**
+   * @note Use a proxy TypeScript configuration where the "compilerOptions.composite"
+   * option is set to false.
+   * @see https://github.com/egoist/tsup/issues/571
+   */
+  tsconfig: path.resolve(__dirname, 'src/browser/tsconfig.browser.build.json'),
   define: {
     SERVICE_WORKER_CHECKSUM: JSON.stringify(SERVICE_WORKER_CHECKSUM),
   },
@@ -78,6 +86,7 @@ const reactNativeConfig: Options = {
   bundle: true,
   splitting: false,
   dts: true,
+  tsconfig: path.resolve(__dirname, 'src/tsconfig.node.build.json'),
   esbuildPlugins: [resolveCoreImportsPlugin(), forceEsmExtensionsPlugin()],
 }
 
@@ -96,6 +105,7 @@ const iifeConfig: Options = {
   bundle: true,
   splitting: false,
   dts: false,
+  tsconfig: path.resolve(__dirname, 'src/browser/tsconfig.browser.build.json'),
   define: {
     // Sign the IIFE build as well because any bundle containing
     // the worker API must have the the integrity checksum defined.