diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 270886ad604..987de003417 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,5 +1,5 @@
 {
-  "google-apis-core": "1.0.0",
+  "google-apis-core": "1.0.1",
   "google-apis-core+FILLER": "0.0.0",
   "google-apis-generator": "0.18.0",
   "google-apis-generator+FILLER": "0.0.0"
diff --git a/google-apis-core/CHANGELOG.md b/google-apis-core/CHANGELOG.md
index 31f9bc9122f..1673981b4ef 100644
--- a/google-apis-core/CHANGELOG.md
+++ b/google-apis-core/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Release History
 
+### 1.0.1 (2025-08-08)
+
+#### Bug Fixes
+
+* Compute and send content-length header when posting a CompositeIO ([#23864](https://github.com/googleapis/google-api-ruby-client/issues/23864)) 
+
 ### 1.0.0 (2025-08-03)
 
 This is a major release that replaces the underlying httpclient library with Faraday ([#23524](https://github.com/googleapis/google-api-ruby-client/issues/23524)). This will ensure the client libraries are on a more stable and better maintained foundation moving forward.
diff --git a/google-apis-core/lib/google/apis/core/version.rb b/google-apis-core/lib/google/apis/core/version.rb
index 05fe7d92673..5da83117e5d 100644
--- a/google-apis-core/lib/google/apis/core/version.rb
+++ b/google-apis-core/lib/google/apis/core/version.rb
@@ -16,7 +16,7 @@ module Google
   module Apis
     module Core
       # Core version
-      VERSION = "1.0.0".freeze
+      VERSION = "1.0.1".freeze
     end
   end
 end