diff --git a/packages/mui-material-next/src/FilledInput/FilledInput.tsx b/packages/mui-material-next/src/FilledInput/FilledInput.tsx
index 5e4cb3655a1ef8..5b50df431318bb 100644
--- a/packages/mui-material-next/src/FilledInput/FilledInput.tsx
+++ b/packages/mui-material-next/src/FilledInput/FilledInput.tsx
@@ -460,7 +460,6 @@ FilledInput.propTypes /* remove-proptypes */ = {
   slots: PropTypes.shape({
     input: PropTypes.elementType,
     root: PropTypes.elementType,
-    textarea: PropTypes.elementType,
   }),
   /**
    * Start `InputAdornment` for this component.
diff --git a/packages/mui-material-next/src/FilledInput/FilledInput.types.ts b/packages/mui-material-next/src/FilledInput/FilledInput.types.ts
index aa76a32c9cc3d2..81a694f2085274 100644
--- a/packages/mui-material-next/src/FilledInput/FilledInput.types.ts
+++ b/packages/mui-material-next/src/FilledInput/FilledInput.types.ts
@@ -7,7 +7,7 @@ import { Theme } from '../styles/Theme.types';
 import { InputBaseProps } from '../InputBase/InputBase.types';
 import { FilledInputClasses } from './filledInputClasses';
 
-export type FilledInputOwnProps = StandardProps<InputBaseProps> & {
+export type FilledInputOwnProps = StandardProps<Omit<InputBaseProps, 'slots'>> & {
   /**
    * Override or extend the styles applied to the component.
    */
@@ -23,12 +23,31 @@ export type FilledInputOwnProps = StandardProps<InputBaseProps> & {
    * If `true`, the input will not have an underline.
    */
   disableUnderline?: boolean;
+  /**
+   * The components used for each slot inside the InputBase.
+   * Either a string to use a HTML element or a component.
+   * @default {}
+   */
+  slots?: FilledInputSlots;
   /**
    * The system prop that allows defining system overrides as well as additional CSS styles.
    */
   sx?: SxProps<Theme>;
 };
 
+export interface FilledInputSlots {
+  /**
+   * The component that renders the root.
+   * @default 'div'
+   */
+  root?: React.ElementType;
+  /**
+   * The component that renders the input.
+   * @default 'input'
+   */
+  input?: React.ElementType;
+}
+
 export interface FilledInputTypeMap<
   AdditionalProps = {},
   RootComponentType extends React.ElementType = 'div',