diff --git a/.changeset/popular-cups-melt.md b/.changeset/popular-cups-melt.md
new file mode 100644
index 00000000000..b5b662a6337
--- /dev/null
+++ b/.changeset/popular-cups-melt.md
@@ -0,0 +1,7 @@
+---
+"firebase": patch
+"@firebase/storage-types": patch
+"@firebase/storage": patch
+---
+
+[fix] Updated the TypeScript types for all APIs using Observers to allow callback omission. 
diff --git a/packages/firebase/index.d.ts b/packages/firebase/index.d.ts
index 518f22d130a..83488fa28b3 100644
--- a/packages/firebase/index.d.ts
+++ b/packages/firebase/index.d.ts
@@ -7579,7 +7579,7 @@ declare namespace firebase.storage {
     on(
       event: firebase.storage.TaskEvent,
       nextOrObserver?:
-        | firebase.Observer<UploadTaskSnapshot>
+        | Partial<firebase.Observer<UploadTaskSnapshot>>
         | null
         | ((a: UploadTaskSnapshot) => any),
       error?: ((a: Error) => any) | null,
diff --git a/packages/storage-types/index.d.ts b/packages/storage-types/index.d.ts
index 4aa67a6c8bd..902461581cc 100644
--- a/packages/storage-types/index.d.ts
+++ b/packages/storage-types/index.d.ts
@@ -91,7 +91,7 @@ export interface UploadTask {
   on(
     event: TaskEvent,
     nextOrObserver?:
-      | Observer<UploadTaskSnapshot>
+      | Partial<Observer<UploadTaskSnapshot>>
       | null
       | ((a: UploadTaskSnapshot) => any),
     error?: ((a: Error) => any) | null,