diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 3dc996801..030ceec1f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,4 +1,4 @@
 {
-  "gax": "4.2.0",
+  "gax": "4.2.1",
   "tools": "0.3.0"
 }
diff --git a/gax/CHANGELOG.md b/gax/CHANGELOG.md
index eaf598ad8..bb5c50b59 100644
--- a/gax/CHANGELOG.md
+++ b/gax/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://www.npmjs.com/package/gax-nodejs?activeTab=versions
 
+## [4.2.1](https://github.com/googleapis/gax-nodejs/compare/v4.2.0...v4.2.1) (2024-01-26)
+
+
+### Bug Fixes
+
+* run update-protos to include new field_info.proto ([#1547](https://github.com/googleapis/gax-nodejs/issues/1547)) ([ae37986](https://github.com/googleapis/gax-nodejs/commit/ae37986ddc9f6c822ff557248cdf68529931abc6))
+
 ## [4.2.0](https://github.com/googleapis/gax-nodejs/compare/v4.1.0...v4.2.0) (2024-01-18)
 
 
diff --git a/gax/package.json b/gax/package.json
index af8604ec7..2160985cf 100644
--- a/gax/package.json
+++ b/gax/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-gax",
-  "version": "4.2.0",
+  "version": "4.2.1",
   "description": "Google API Extensions",
   "main": "build/src/index.js",
   "types": "build/src/index.d.ts",
diff --git a/gax/samples/package.json b/gax/samples/package.json
index f977b6c74..0ffc8114f 100644
--- a/gax/samples/package.json
+++ b/gax/samples/package.json
@@ -14,7 +14,7 @@
     "*.js"
   ],
   "dependencies": {
-    "google-gax": "^4.2.0"
+    "google-gax": "^4.2.1"
   },
   "devDependencies": {
     "c8": "^9.0.0",