diff --git a/package.json b/package.json
index 14e8cf9..89dab73 100644
--- a/package.json
+++ b/package.json
@@ -66,7 +66,9 @@
     "test:examples": "vitest run examples --coverage",
     "types": "svelte-check",
     "types:legacy": "svelte-check --tsconfig tsconfig.legacy.json",
-    "build": "tsc -p tsconfig.build.json && cp src/component-types.d.ts types",
+    "build": "npm-run-all build:*",
+    "build:tsc": "tsc -p tsconfig.build.json",
+    "build:copy-dts": "cp src/core/types.d.ts types/core",
     "contributors:add": "all-contributors add",
     "contributors:generate": "all-contributors generate",
     "preview-release": "./scripts/preview-release",
diff --git a/src/core/index.js b/src/core/index.js
index 9e41adf..4155764 100644
--- a/src/core/index.js
+++ b/src/core/index.js
@@ -5,15 +5,15 @@
  * Will switch to legacy, class-based mounting logic
  * if it looks like we're in a Svelte <= 4 environment.
  */
-import * as LegacyCore from './legacy.js'
-import * as ModernCore from './modern.svelte.js'
-import { createValidateOptions } from './validate-options.js'
+import * as MountLegacy from './mount-legacy.js'
+import * as MountModern from './mount-modern.svelte.js'
+import { createValidateOptions } from './prepare.js'
 
 const { mount, unmount, updateProps, allowedOptions } =
-  ModernCore.IS_MODERN_SVELTE ? ModernCore : LegacyCore
+  MountModern.IS_MODERN_SVELTE ? MountModern : MountLegacy
 
 /** Validate component options. */
 const validateOptions = createValidateOptions(allowedOptions)
 
 export { mount, unmount, updateProps, validateOptions }
-export { UnknownSvelteOptionsError } from './validate-options.js'
+export { UnknownSvelteOptionsError } from './prepare.js'
diff --git a/src/core/legacy.js b/src/core/mount-legacy.js
similarity index 100%
rename from src/core/legacy.js
rename to src/core/mount-legacy.js
diff --git a/src/core/modern.svelte.js b/src/core/mount-modern.svelte.js
similarity index 100%
rename from src/core/modern.svelte.js
rename to src/core/mount-modern.svelte.js
diff --git a/src/core/validate-options.js b/src/core/prepare.js
similarity index 100%
rename from src/core/validate-options.js
rename to src/core/prepare.js
diff --git a/src/component-types.d.ts b/src/core/types.d.ts
similarity index 100%
rename from src/component-types.d.ts
rename to src/core/types.d.ts
diff --git a/src/pure.js b/src/pure.js
index 583d063..0ccc4c3 100644
--- a/src/pure.js
+++ b/src/pure.js
@@ -15,8 +15,8 @@ const componentCache = new Set()
 /**
  * Customize how Svelte renders the component.
  *
- * @template {import('./component-types.js').Component} C
- * @typedef {import('./component-types.js').Props<C> | Partial<import('./component-types.js').MountOptions<C>>} SvelteComponentOptions
+ * @template {import('./core/types.js').Component} C
+ * @typedef {import('./core/types.js').Props<C> | Partial<import('./core/types.js').MountOptions<C>>} SvelteComponentOptions
  */
 
 /**
@@ -32,15 +32,15 @@ const componentCache = new Set()
 /**
  * The rendered component and bound testing functions.
  *
- * @template {import('./component-types.js').Component} C
+ * @template {import('./core/types.js').Component} C
  * @template {import('@testing-library/dom').Queries} [Q=typeof import('@testing-library/dom').queries]
  *
  * @typedef {{
  *   container: HTMLElement
  *   baseElement: HTMLElement
- *   component: import('./component-types.js').Exports<C>
+ *   component: import('./core/types.js').Exports<C>
  *   debug: (el?: HTMLElement | DocumentFragment) => void
- *   rerender: (props: Partial<import('./component-types.js').Props<C>>) => Promise<void>
+ *   rerender: (props: Partial<import('./core/types.js').Props<C>>) => Promise<void>
  *   unmount: () => void
  * } & {
  *   [P in keyof Q]: import('@testing-library/dom').BoundFunction<Q[P]>
@@ -50,10 +50,10 @@ const componentCache = new Set()
 /**
  * Render a component into the document.
  *
- * @template {import('./component-types.js').Component} C
+ * @template {import('./core/types.js').Component} C
  * @template {import('@testing-library/dom').Queries} [Q=typeof import('@testing-library/dom').queries]
  *
- * @param {import('./component-types.js').ComponentType<C>} Component - The component to render.
+ * @param {import('./core/types.js').ComponentType<C>} Component - The component to render.
  * @param {SvelteComponentOptions<C>} options - Customize how Svelte renders the component.
  * @param {RenderOptions<Q>} renderOptions - Customize how Testing Library sets up the document and binds queries.
  * @returns {RenderResult<C, Q>} The rendered component and bound testing functions.
diff --git a/tests/render-runes.test-d.ts b/tests/render-runes.test-d.ts
index 1e42544..8c69822 100644
--- a/tests/render-runes.test-d.ts
+++ b/tests/render-runes.test-d.ts
@@ -31,6 +31,7 @@ describe('types', () => {
 
     expectTypeOf(result).toExtend<{
       container: HTMLElement
+      baseElement: HTMLElement
       component: { hello: string }
       debug: (el?: HTMLElement) => void
       rerender: (props: { name?: string; count?: number }) => Promise<void>
diff --git a/tests/render.test-d.ts b/tests/render.test-d.ts
index eb1c639..b4c428e 100644
--- a/tests/render.test-d.ts
+++ b/tests/render.test-d.ts
@@ -39,6 +39,7 @@ describe('types', () => {
 
     expectTypeOf(result).toExtend<{
       container: HTMLElement
+      baseElement: HTMLElement
       component: { hello: string }
       debug: (el?: HTMLElement) => void
       rerender: (props: { name?: string; count?: number }) => Promise<void>