diff --git a/packages/mui-styled-engine/package.json b/packages/mui-styled-engine/package.json
index c86f66b67f0f95..2cdea79bcec3ad 100644
--- a/packages/mui-styled-engine/package.json
+++ b/packages/mui-styled-engine/package.json
@@ -24,7 +24,7 @@
     "url": "https://opencollective.com/mui-org"
   },
   "scripts": {
-    "build": "code-infra build --flat --skipTsc",
+    "build": "code-infra build --flat",
     "release": "pnpm build && pnpm publish",
     "test": "pnpm --workspace-root test:unit --project \"*:@mui/styled-engine\"",
     "typescript": "tsc -p tsconfig.json",
@@ -43,6 +43,7 @@
     "@emotion/styled": "11.14.1",
     "@mui/styled-engine": "workspace:*",
     "@types/chai": "5.2.3",
+    "@types/prop-types": "15.7.15",
     "@types/react": "19.2.14",
     "chai": "6.2.2",
     "react": "19.2.6"
@@ -69,7 +70,7 @@
     "node": ">=14.0.0"
   },
   "exports": {
-    ".": "./src/index.js",
-    "./*": "./src/*/index.js"
+    ".": "./src/index.ts",
+    "./*": "./src/*/index.ts"
   }
 }
diff --git a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.d.ts b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.d.ts
deleted file mode 100644
index 0d6af5c9d1d5f6..00000000000000
--- a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.d.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import * as React from 'react';
-import { Interpolation } from '@emotion/react';
-
-export interface GlobalStylesProps<Theme = {}> {
-  defaultTheme?: object | undefined;
-  styles: Interpolation<Theme>;
-}
-
-export default function GlobalStyles<Theme = {}>(
-  props: GlobalStylesProps<Theme>,
-): React.JSX.Element;
diff --git a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.js b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.js
deleted file mode 100644
index daf5648781e79e..00000000000000
--- a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.js
+++ /dev/null
@@ -1,28 +0,0 @@
-'use client';
-import PropTypes from 'prop-types';
-import { Global } from '@emotion/react';
-
-function isEmpty(obj) {
-  return obj === undefined || obj === null || Object.keys(obj).length === 0;
-}
-
-export default function GlobalStyles(props) {
-  const { styles, defaultTheme = {} } = props;
-
-  const globalStyles =
-    typeof styles === 'function'
-      ? (themeInput) => styles(isEmpty(themeInput) ? defaultTheme : themeInput)
-      : styles;
-
-  return <Global styles={globalStyles} />;
-}
-
-GlobalStyles.propTypes = {
-  defaultTheme: PropTypes.object,
-  styles: PropTypes.oneOfType([
-    PropTypes.array,
-    PropTypes.string,
-    PropTypes.object,
-    PropTypes.func,
-  ]),
-};
diff --git a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.js b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.tsx
similarity index 93%
rename from packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.js
rename to packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.tsx
index e84d022ec94d76..b56a5a2ddc51b8 100644
--- a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.js
+++ b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.test.tsx
@@ -36,7 +36,7 @@ describe('GlobalStyles', () => {
   it.skipIf(isJsdom())('should add global styles using function', function test() {
     render(
       <ThemeProvider theme={{ color: 'rgb(0, 0, 255)' }}>
-        <GlobalStyles styles={(theme) => ({ span: { color: theme.color } })} />
+        <GlobalStyles styles={(theme: any) => ({ span: { color: theme.color } })} />
         <span data-testid="text">Blue text</span>
       </ThemeProvider>,
     );
@@ -51,7 +51,7 @@ describe('GlobalStyles', () => {
       render(
         <GlobalStyles
           defaultTheme={{ color: 'rgb(0, 0, 255)' }}
-          styles={(theme) => ({ span: { color: theme.color } })}
+          styles={(theme: any) => ({ span: { color: theme.color } })}
         />,
       ),
     ).not.to.throw();
diff --git a/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.tsx b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.tsx
new file mode 100644
index 00000000000000..5df1fb8879e130
--- /dev/null
+++ b/packages/mui-styled-engine/src/GlobalStyles/GlobalStyles.tsx
@@ -0,0 +1,39 @@
+'use client';
+import type * as React from 'react';
+import PropTypes from 'prop-types';
+import { Global, type Interpolation } from '@emotion/react';
+
+export interface GlobalStylesProps<Theme = {}> {
+  defaultTheme?: object | undefined;
+  styles: Interpolation<Theme>;
+}
+
+function isEmpty(obj: object | null | undefined) {
+  return obj === undefined || obj === null || Object.keys(obj).length === 0;
+}
+
+export default function GlobalStyles<Theme = {}>(
+  props: GlobalStylesProps<Theme>,
+): React.JSX.Element {
+  const { styles, defaultTheme = {} } = props;
+
+  const globalStyles =
+    typeof styles === 'function'
+      ? (themeInput: Theme) =>
+          (styles as (theme: Theme) => Interpolation<Theme>)(
+            isEmpty(themeInput as object) ? (defaultTheme as Theme) : themeInput,
+          )
+      : styles;
+
+  return <Global styles={globalStyles as any} />;
+}
+
+(GlobalStyles as any).propTypes /* remove-proptypes */ = {
+  defaultTheme: PropTypes.object,
+  styles: PropTypes.oneOfType([
+    PropTypes.array,
+    PropTypes.string,
+    PropTypes.object,
+    PropTypes.func,
+  ]),
+};
diff --git a/packages/mui-styled-engine/src/GlobalStyles/index.d.ts b/packages/mui-styled-engine/src/GlobalStyles/index.d.ts
deleted file mode 100644
index a815f5c4a572b2..00000000000000
--- a/packages/mui-styled-engine/src/GlobalStyles/index.d.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-export { default } from './GlobalStyles';
-export * from './GlobalStyles';
diff --git a/packages/mui-styled-engine/src/GlobalStyles/index.js b/packages/mui-styled-engine/src/GlobalStyles/index.ts
similarity index 53%
rename from packages/mui-styled-engine/src/GlobalStyles/index.js
rename to packages/mui-styled-engine/src/GlobalStyles/index.ts
index 48e20189092434..ce5e5f82dff052 100644
--- a/packages/mui-styled-engine/src/GlobalStyles/index.js
+++ b/packages/mui-styled-engine/src/GlobalStyles/index.ts
@@ -1 +1,2 @@
 export { default } from './GlobalStyles';
+export type * from './GlobalStyles';
diff --git a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.d.ts b/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.d.ts
deleted file mode 100644
index ed7af7d5adefcd..00000000000000
--- a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.d.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import * as React from 'react';
-
-export interface StyledEngineProviderProps {
-  children?: React.ReactNode;
-  enableCssLayer?: boolean | undefined;
-  injectFirst?: boolean | undefined;
-}
-
-export default function StyledEngineProvider(props: StyledEngineProviderProps): React.JSX.Element;
diff --git a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.js b/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.tsx
similarity index 96%
rename from packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.js
rename to packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.tsx
index b691c42cda2369..f1dd817c327efa 100644
--- a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.js
+++ b/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.test.tsx
@@ -7,10 +7,10 @@ import { TEST_INTERNALS_DO_NOT_USE } from './StyledEngineProvider';
 describe('[Emotion] StyledEngineProvider', () => {
   const { render } = createRenderer();
 
-  let rule;
+  let rule: string | undefined;
 
   beforeAll(() => {
-    TEST_INTERNALS_DO_NOT_USE.insert = (...args) => {
+    TEST_INTERNALS_DO_NOT_USE.insert = (...args: any[]) => {
       rule = args[0];
     };
   });
diff --git a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.js b/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.tsx
similarity index 80%
rename from packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.js
rename to packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.tsx
index 4a2af3ef79a953..d760e297473208 100644
--- a/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.js
+++ b/packages/mui-styled-engine/src/StyledEngineProvider/StyledEngineProvider.tsx
@@ -5,13 +5,24 @@ import { CacheProvider } from '@emotion/react';
 import createCache from '@emotion/cache';
 import { StyleSheet } from '@emotion/sheet';
 
+export interface StyledEngineProviderProps {
+  children?: React.ReactNode;
+  enableCssLayer?: boolean | undefined;
+  injectFirst?: boolean | undefined;
+}
+
 // To fix [Jest performance](https://github.com/mui/material-ui/issues/45638).
 const cacheMap = new Map();
 
 // Need to add a private variable to test the generated CSS from Emotion, this is the simplest way to do it.
 // We can't test the CSS from `style` tag easily because the `speedy: true` (produce empty text content) is enabled by Emotion.
 // Even if we disable it, JSDOM needs extra configuration to be able to parse `@layer` CSS.
-export const TEST_INTERNALS_DO_NOT_USE = {
+/**
+ * @internal
+ */
+export const TEST_INTERNALS_DO_NOT_USE: {
+  insert?: ((rule: string, options?: unknown) => unknown) | undefined;
+} = {
   /**
    * to intercept the generated CSS before inserting to the style tag, so that we can check the generated CSS.
    *
@@ -27,7 +38,7 @@ export const TEST_INTERNALS_DO_NOT_USE = {
 
 // We might be able to remove this when this issue is fixed:
 // https://github.com/emotion-js/emotion/issues/2790
-const createEmotionCache = (options, CustomSheet) => {
+const createEmotionCache = (options: any, CustomSheet: any) => {
   const cache = createCache(options);
 
   // Do the same as https://github.com/emotion-js/emotion/blob/main/packages/cache/src/index.js#L238-L245
@@ -43,7 +54,7 @@ const createEmotionCache = (options, CustomSheet) => {
   return cache;
 };
 
-let insertionPoint;
+let insertionPoint: any;
 if (typeof document === 'object') {
   // Use `insertionPoint` over `prepend`(deprecated) because it can be controlled for GlobalStyles injection order
   // For more information, see https://github.com/mui/material-ui/issues/44597
@@ -59,7 +70,7 @@ if (typeof document === 'object') {
   }
 }
 
-function getCache(injectFirst, enableCssLayer) {
+function getCache(injectFirst?: boolean, enableCssLayer?: boolean) {
   if (injectFirst || enableCssLayer) {
     /**
      * This is for client-side apps only.
@@ -67,14 +78,14 @@ function getCache(injectFirst, enableCssLayer) {
      * This is because the [sheet](https://github.com/emotion-js/emotion/blob/main/packages/react/src/global.js#L94-L99) does not consume the options.
      */
     class MyStyleSheet extends StyleSheet {
-      insert(rule, options) {
+      insert(rule: string, options?: unknown): unknown {
         if (TEST_INTERNALS_DO_NOT_USE.insert) {
           return TEST_INTERNALS_DO_NOT_USE.insert(rule, options);
         }
         if (this.key && this.key.endsWith('global')) {
           this.before = insertionPoint;
         }
-        return super.insert(rule, options);
+        return (super.insert as (rule: string, options?: unknown) => unknown)(rule, options);
       }
     }
     const emotionCache = createEmotionCache(
@@ -86,12 +97,12 @@ function getCache(injectFirst, enableCssLayer) {
     );
     if (enableCssLayer) {
       const prevInsert = emotionCache.insert;
-      emotionCache.insert = (...args) => {
+      (emotionCache as any).insert = (...args: any[]) => {
         if (!args[1].styles.match(/^@layer\s+[^{]*$/)) {
           // avoid nested @layer
           args[1].styles = `@layer mui {${args[1].styles}}`;
         }
-        return prevInsert(...args);
+        return (prevInsert as (...insertArgs: any[]) => unknown)(...args);
       };
     }
     return emotionCache;
@@ -99,7 +110,7 @@ function getCache(injectFirst, enableCssLayer) {
   return undefined;
 }
 
-export default function StyledEngineProvider(props) {
+export default function StyledEngineProvider(props: StyledEngineProviderProps): React.JSX.Element {
   const { injectFirst, enableCssLayer, children } = props;
   const cache = React.useMemo(() => {
     const cacheKey = `${injectFirst}-${enableCssLayer}`;
@@ -110,10 +121,12 @@ export default function StyledEngineProvider(props) {
     cacheMap.set(cacheKey, fresh);
     return fresh;
   }, [injectFirst, enableCssLayer]);
-  return cache ? <CacheProvider value={cache}>{children}</CacheProvider> : children;
+  return (
+    cache ? <CacheProvider value={cache}>{children}</CacheProvider> : children
+  ) as React.JSX.Element;
 }
 
-StyledEngineProvider.propTypes = {
+(StyledEngineProvider as any).propTypes /* remove-proptypes */ = {
   /**
    * Your component tree.
    */
diff --git a/packages/mui-styled-engine/src/StyledEngineProvider/index.js b/packages/mui-styled-engine/src/StyledEngineProvider/index.js
deleted file mode 100644
index 30cd6986a545fa..00000000000000
--- a/packages/mui-styled-engine/src/StyledEngineProvider/index.js
+++ /dev/null
@@ -1 +0,0 @@
-export { default } from './StyledEngineProvider';
diff --git a/packages/mui-styled-engine/src/StyledEngineProvider/index.d.ts b/packages/mui-styled-engine/src/StyledEngineProvider/index.ts
similarity index 52%
rename from packages/mui-styled-engine/src/StyledEngineProvider/index.d.ts
rename to packages/mui-styled-engine/src/StyledEngineProvider/index.ts
index 7fdd272b28e6ca..99ecbcdd5854ac 100644
--- a/packages/mui-styled-engine/src/StyledEngineProvider/index.d.ts
+++ b/packages/mui-styled-engine/src/StyledEngineProvider/index.ts
@@ -1,2 +1,2 @@
 export { default } from './StyledEngineProvider';
-export * from './StyledEngineProvider';
+export type * from './StyledEngineProvider';
diff --git a/packages/mui-styled-engine/src/index.js b/packages/mui-styled-engine/src/index.js
deleted file mode 100644
index 60431f3c814636..00000000000000
--- a/packages/mui-styled-engine/src/index.js
+++ /dev/null
@@ -1,50 +0,0 @@
-'use client';
-/* eslint-disable no-underscore-dangle */
-import emStyled from '@emotion/styled';
-import { serializeStyles as emSerializeStyles } from '@emotion/serialize';
-
-export default function styled(tag, options) {
-  const stylesFactory = emStyled(tag, options);
-
-  if (process.env.NODE_ENV !== 'production') {
-    return (...styles) => {
-      const component = typeof tag === 'string' ? `"${tag}"` : 'component';
-      if (styles.length === 0) {
-        console.error(
-          [
-            `MUI: Seems like you called \`styled(${component})()\` without a \`style\` argument.`,
-            'You must provide a `styles` argument: `styled("div")(styleYouForgotToPass)`.',
-          ].join('\n'),
-        );
-      } else if (styles.some((style) => style === undefined)) {
-        console.error(
-          `MUI: the styled(${component})(...args) API requires all its args to be defined.`,
-        );
-      }
-      return stylesFactory(...styles);
-    };
-  }
-
-  return stylesFactory;
-}
-
-// eslint-disable-next-line @typescript-eslint/naming-convention
-export function internal_mutateStyles(tag, processor) {
-  // Emotion attaches all the styles as `__emotion_styles`.
-  // Ref: https://github.com/emotion-js/emotion/blob/16d971d0da229596d6bcc39d282ba9753c9ee7cf/packages/styled/src/base.js#L186
-  if (Array.isArray(tag.__emotion_styles)) {
-    tag.__emotion_styles = processor(tag.__emotion_styles);
-  }
-}
-
-// Emotion only accepts an array, but we want to avoid allocations
-const wrapper = [];
-// eslint-disable-next-line @typescript-eslint/naming-convention
-export function internal_serializeStyles(styles) {
-  wrapper[0] = styles;
-  return emSerializeStyles(wrapper);
-}
-
-export { ThemeContext, keyframes, css } from '@emotion/react';
-export { default as StyledEngineProvider } from './StyledEngineProvider';
-export { default as GlobalStyles } from './GlobalStyles';
diff --git a/packages/mui-styled-engine/src/index.d.ts b/packages/mui-styled-engine/src/index.ts
similarity index 75%
rename from packages/mui-styled-engine/src/index.d.ts
rename to packages/mui-styled-engine/src/index.ts
index 93aa5c0a244aa6..d76a00ab8d2f6f 100644
--- a/packages/mui-styled-engine/src/index.d.ts
+++ b/packages/mui-styled-engine/src/index.ts
@@ -1,21 +1,48 @@
-import * as CSS from 'csstype';
-import { StyledComponent, StyledOptions } from '@emotion/styled';
-import { PropsOf } from '@emotion/react';
-
-export * from '@emotion/styled';
-export { default } from '@emotion/styled';
-export { ThemeContext, keyframes, css } from '@emotion/react';
-
-export { default as StyledEngineProvider } from './StyledEngineProvider';
-
-export { default as GlobalStyles } from './GlobalStyles';
-export * from './GlobalStyles';
+'use client';
+/* eslint-disable no-underscore-dangle */
+import emStyled, {
+  type CreateStyled,
+  type StyledComponent,
+  type StyledOptions,
+} from '@emotion/styled';
+import { serializeStyles as emSerializeStyles } from '@emotion/serialize';
+import type * as CSS from 'csstype';
+import { type PropsOf } from '@emotion/react';
+
+// Re-export the public type surface of `@emotion/styled`. Explicit names rather
+// than `export type *`: an `export *` (even type-only) is disallowed by the
+// `'use client'` Next.js lint rule. Names locally redeclared below intentionally
+// shadow Emotion's and are not re-exported here.
+export type { CreateStyled, StyledComponent, StyledOptions, StyledTags } from '@emotion/styled';
+
+function styled(tag: React.ElementType, options?: StyledOptions<any>) {
+  // Emotion's `styled` overloads each expect a specific tag/component shape;
+  // none accept the broadened `React.ElementType` union, so cast the passthrough.
+  const stylesFactory = emStyled(tag as any, options);
+
+  if (process.env.NODE_ENV !== 'production') {
+    return (...styles: any[]) => {
+      const component = typeof tag === 'string' ? `"${tag}"` : 'component';
+      if (styles.length === 0) {
+        console.error(
+          [
+            `MUI: Seems like you called \`styled(${component})()\` without a \`style\` argument.`,
+            'You must provide a `styles` argument: `styled("div")(styleYouForgotToPass)`.',
+          ].join('\n'),
+        );
+      } else if (styles.some((style) => style === undefined)) {
+        console.error(
+          `MUI: the styled(${component})(...args) API requires all its args to be defined.`,
+        );
+      }
+      return stylesFactory(...styles);
+    };
+  }
+
+  return stylesFactory;
+}
 
-export type MUIStyledComponent<
-  ComponentProps extends {},
-  SpecificComponentProps extends {} = {},
-  JSXProps extends {} = {},
-> = StyledComponent<ComponentProps, SpecificComponentProps, JSXProps>;
+export default styled as unknown as CreateStyled;
 
 /**
  * For internal usage in `@mui/system` package
@@ -24,10 +51,32 @@ export type MUIStyledComponent<
 export function internal_mutateStyles(
   tag: React.ElementType,
   processor: (styles: any) => any,
-): void;
+): void {
+  // Emotion attaches all the styles as `__emotion_styles`.
+  // Ref: https://github.com/emotion-js/emotion/blob/16d971d0da229596d6bcc39d282ba9753c9ee7cf/packages/styled/src/base.js#L186
+  if (Array.isArray((tag as any).__emotion_styles)) {
+    (tag as any).__emotion_styles = processor((tag as any).__emotion_styles);
+  }
+}
 
+// Emotion only accepts an array, but we want to avoid allocations
+const wrapper: any[] = [];
 // eslint-disable-next-line @typescript-eslint/naming-convention
-export function internal_serializeStyles<P>(styles: Interpolation<P>): object;
+export function internal_serializeStyles<P>(styles: Interpolation<P>): object {
+  wrapper[0] = styles;
+  return emSerializeStyles(wrapper);
+}
+
+export { ThemeContext, keyframes, css } from '@emotion/react';
+export { default as StyledEngineProvider } from './StyledEngineProvider';
+export { default as GlobalStyles } from './GlobalStyles';
+export type { GlobalStylesProps } from './GlobalStyles';
+
+export type MUIStyledComponent<
+  ComponentProps extends {},
+  SpecificComponentProps extends {} = {},
+  JSXProps extends {} = {},
+> = StyledComponent<ComponentProps, SpecificComponentProps, JSXProps>;
 
 export interface SerializedStyles {
   name: string;
@@ -126,7 +175,7 @@ export type Interpolation<Props> =
   | ArrayInterpolation<Props>
   | FunctionInterpolation<Props>;
 
-export function shouldForwardProp(propName: PropertyKey): boolean;
+export declare function shouldForwardProp(propName: PropertyKey): boolean;
 
 /** Same as StyledOptions but shouldForwardProp must be a type guard */
 export interface FilteringStyledOptions<Props, ForwardedProps extends keyof Props = keyof Props> {
diff --git a/packages/mui-styled-engine/src/styled.test.js b/packages/mui-styled-engine/src/styled.test.ts
similarity index 100%
rename from packages/mui-styled-engine/src/styled.test.js
rename to packages/mui-styled-engine/src/styled.test.ts
diff --git a/packages/mui-styled-engine/tsconfig.build.json b/packages/mui-styled-engine/tsconfig.build.json
new file mode 100644
index 00000000000000..fb7bbbba3f40ca
--- /dev/null
+++ b/packages/mui-styled-engine/tsconfig.build.json
@@ -0,0 +1,17 @@
+// This config is for emitting declarations (.d.ts) only
+// Actual .ts source files are transpiled via babel
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "composite": true,
+    "declaration": true,
+    "noEmit": false,
+    "emitDeclarationOnly": true,
+    "outDir": "build",
+    "rootDir": "./src",
+    "stripInternal": true,
+    "types": ["@mui/internal-code-infra/build-env", "react"]
+  },
+  "include": ["src/**/*.ts", "src/**/*.tsx"],
+  "exclude": ["src/**/*.test.ts*", "src/**/*.spec.ts*"]
+}
diff --git a/packages/mui-styled-engine/tsconfig.json b/packages/mui-styled-engine/tsconfig.json
index cbfffafe5ca1e7..fc9e91137dd7f5 100644
--- a/packages/mui-styled-engine/tsconfig.json
+++ b/packages/mui-styled-engine/tsconfig.json
@@ -1,5 +1,9 @@
 {
   "extends": "../../tsconfig.json",
-
+  "compilerOptions": {
+    "allowJs": false,
+    "skipLibCheck": true,
+    "types": ["react", "vitest/globals", "@mui/internal-code-infra/build-env"]
+  },
   "include": ["src/**/*"]
 }
diff --git a/packages/mui-system/tsconfig.build.json b/packages/mui-system/tsconfig.build.json
index 7696cbeba02fc7..b143a0736570c0 100644
--- a/packages/mui-system/tsconfig.build.json
+++ b/packages/mui-system/tsconfig.build.json
@@ -12,5 +12,8 @@
   },
   "include": ["src/**/*.ts*"],
   "exclude": ["src/**/*.spec.ts*", "src/**/*.test.ts*"],
-  "references": [{ "path": "../mui-utils/tsconfig.build.json" }]
+  "references": [
+    { "path": "../mui-styled-engine/tsconfig.build.json" },
+    { "path": "../mui-utils/tsconfig.build.json" }
+  ]
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 2c47f093ca5994..9639a43d79a965 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1317,6 +1317,9 @@ importers:
       '@types/chai':
         specifier: 5.2.3
         version: 5.2.3
+      '@types/prop-types':
+        specifier: 15.7.15
+        version: 15.7.15
       '@types/react':
         specifier: 19.2.14
         version: 19.2.14