diff --git a/packages/oauth/src/index.ts b/packages/oauth/src/index.ts
index 96b4f15a9..70b39a37a 100644
--- a/packages/oauth/src/index.ts
+++ b/packages/oauth/src/index.ts
@@ -456,7 +456,8 @@ export interface InstallationStore {
     logger?: Logger): Promise<void>;
   fetchInstallation:
     (query: InstallationQuery<boolean>, logger?: Logger) => Promise<Installation<'v1' | 'v2', boolean>>;
-  deleteInstallation:
+  // TODO :: remove optionality in v3.0
+  deleteInstallation?:
     (query: InstallationQuery<boolean>, logger?: Logger) => Promise<void>;
 }