diff --git a/code/lib/core-common/src/types.ts b/code/lib/core-common/src/types.ts
index 9555ffe2747f..f0fa900fc4c0 100644
--- a/code/lib/core-common/src/types.ts
+++ b/code/lib/core-common/src/types.ts
@@ -428,6 +428,15 @@ export interface StorybookConfig {
    * Docs related features in index generation
    */
   docs?: DocsOptions;
+
+  /**
+   * Programmatically modify the preview head/body HTML.
+   * The previewHead and previewBody functions accept a string,
+   * which is the existing head/body, and return a modified string.
+   */
+  previewHead?: (head: string, options: Options) => string;
+
+  previewBody?: (body: string, options: Options) => string;
 }
 
 export type PresetProperty<K, TStorybookConfig = StorybookConfig> =