diff --git a/docs/pages/api-docs/snackbar.json b/docs/pages/api-docs/snackbar.json
index db3f0416297c06..af6eb6327891f3 100644
--- a/docs/pages/api-docs/snackbar.json
+++ b/docs/pages/api-docs/snackbar.json
@@ -14,7 +14,7 @@
     "ClickAwayListenerProps": { "type": { "name": "object" } },
     "ContentProps": { "type": { "name": "object" } },
     "disableWindowBlurListener": { "type": { "name": "bool" } },
-    "key": { "type": { "name": "any" } },
+    "key": { "type": { "name": "custom", "description": "any" } },
     "message": { "type": { "name": "node" } },
     "onClose": { "type": { "name": "func" } },
     "open": { "type": { "name": "bool" } },
diff --git a/docs/src/modules/utils/generatePropTypeDescription.ts b/docs/src/modules/utils/generatePropTypeDescription.ts
index 5f339bfe3c14e1..e2d30848e2801c 100644
--- a/docs/src/modules/utils/generatePropTypeDescription.ts
+++ b/docs/src/modules/utils/generatePropTypeDescription.ts
@@ -86,6 +86,9 @@ export default function generatePropTypeDescription(type: PropTypeDescriptor): s
       if (type.raw === 'HTMLElementType') {
         return 'HTML element';
       }
+      if (type.raw === '() => null') {
+        return 'any';
+      }
 
       const deprecatedInfo = getDeprecatedInfo(type);
       if (deprecatedInfo !== false) {
diff --git a/packages/material-ui/src/Snackbar/Snackbar.js b/packages/material-ui/src/Snackbar/Snackbar.js
index 62e4d39ec7fcc0..b71e6d535c67e7 100644
--- a/packages/material-ui/src/Snackbar/Snackbar.js
+++ b/packages/material-ui/src/Snackbar/Snackbar.js
@@ -297,7 +297,7 @@ Snackbar.propTypes /* remove-proptypes */ = {
    * e.g. <Snackbar key={message} />, otherwise, the message may update-in-place and
    * features such as autoHideDuration may be canceled.
    */
-  key: PropTypes.any,
+  key: () => null,
   /**
    * The message to display.
    */
diff --git a/packages/typescript-to-proptypes/src/generator.ts b/packages/typescript-to-proptypes/src/generator.ts
index ae709f6cd3cfb0..165db919624fcb 100644
--- a/packages/typescript-to-proptypes/src/generator.ts
+++ b/packages/typescript-to-proptypes/src/generator.ts
@@ -161,6 +161,12 @@ export function generate(component: t.Component, options: GenerateOptions = {}):
     }
 
     if (propType.type === 'any') {
+      // key isn't a prop like the others, see
+      // https://github.com/mui-org/material-ui/issues/25304
+      if (context.propTypeDefinition.name === 'key') {
+        return '() => null';
+      }
+
       return `${importedName}.any`;
     }
 
diff --git a/packages/typescript-to-proptypes/test/injector/should-include-filename-based/output.js b/packages/typescript-to-proptypes/test/injector/should-include-filename-based/output.js
index ed64a09559357f..7e2c223844b605 100644
--- a/packages/typescript-to-proptypes/test/injector/should-include-filename-based/output.js
+++ b/packages/typescript-to-proptypes/test/injector/should-include-filename-based/output.js
@@ -9,7 +9,7 @@ Snackbar.propTypes = {
   /**
    * some hints about state reset that relates to prop of this component
    */
-  key: PropTypes.any,
+  key: () => null,
 };
 
 export { Snackbar };