diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d69ef8fb3..a5c08b5cd7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 "You know what they say. Fool me once, strike one, but fool me twice... strike three." — Michael Scott
 
+## Unreleased
+
+### Deprecations
+
+- Added a deprecation notice for release bundle uploads, a legacy method for uploading sourcemaps ([#2844](https://github.com/getsentry/sentry-cli/pull/2844)). Release bundle uploads will be removed in Sentry CLI 3.x in favor of artifact bundles, the newer sourcemap upload method [introduced in Sentry version 23.6.2](https://github.com/getsentry/sentry/commit/f90f764fda09575f3f94caf32d04589098384616). **Self-hosted users**: You must upgrade to Sentry 23.6.2 or later before upgrading to Sentry CLI 3.x.
+
 ## 2.56.1
 
 ### Deprecations
diff --git a/src/api/mod.rs b/src/api/mod.rs
index a125ca3501..f90ae34188 100644
--- a/src/api/mod.rs
+++ b/src/api/mod.rs
@@ -991,6 +991,7 @@ impl<'a> AuthenticatedApi<'a> {
             .convert_rnf(ApiErrorKind::ProjectNotFound)
     }
 
+    #[deprecated = "release bundle uploads are deprecated in favor of artifact bundle uploads"]
     pub fn assemble_release_artifacts(
         &self,
         org: &str,
diff --git a/src/utils/file_upload.rs b/src/utils/file_upload.rs
index 15db8419a9..e2c80d2dd3 100644
--- a/src/utils/file_upload.rs
+++ b/src/utils/file_upload.rs
@@ -550,6 +550,14 @@ fn poll_assemble(
                 context.dist,
             )?
         } else {
+            log::warn!(
+                "[DEPRECATION NOTICE] Your Sentry server does not support artifact bundle \
+                uploads. Falling back to deprecated release bundle upload. Support for this \
+                deprecated upload method will be removed in Sentry CLI 3.0.0. Please upgrade your \
+                Sentry server, or if you cannot upgrade, pin your Sentry CLI version to 2.x, so \
+                you don't get upgraded to 3.x when it is released."
+            );
+            #[expect(deprecated, reason = "fallback to legacy upload")]
             authenticated_api.assemble_release_artifacts(
                 context.org,
                 context.release()?,