diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index b386bef..fac1407 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.1.0-alpha.19"
+  ".": "0.1.0-alpha.20"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2270064..42831aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 0.1.0-alpha.20 (2025-02-04)
+
+Full Changelog: [v0.1.0-alpha.19...v0.1.0-alpha.20](https://github.com/nirvana-labs/nirvana-go/compare/v0.1.0-alpha.19...v0.1.0-alpha.20)
+
+### Features
+
+* **client:** send `X-Stainless-Timeout` header ([#80](https://github.com/nirvana-labs/nirvana-go/issues/80)) ([deb01b6](https://github.com/nirvana-labs/nirvana-go/commit/deb01b607f6aa4e9af872d14269fa0c0a38e62cb))
+
 ## 0.1.0-alpha.19 (2025-02-01)
 
 Full Changelog: [v0.1.0-alpha.18...v0.1.0-alpha.19](https://github.com/nirvana-labs/nirvana-go/compare/v0.1.0-alpha.18...v0.1.0-alpha.19)
diff --git a/README.md b/README.md
index b496c9a..bff6fee 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ Or to pin the version:
 <!-- x-release-please-start-version -->
 
 ```sh
-go get -u 'github.com/nirvana-labs/nirvana-go@v0.1.0-alpha.19'
+go get -u 'github.com/nirvana-labs/nirvana-go@v0.1.0-alpha.20'
 ```
 
 <!-- x-release-please-end -->
diff --git a/internal/requestconfig/requestconfig.go b/internal/requestconfig/requestconfig.go
index 0155155..80026db 100644
--- a/internal/requestconfig/requestconfig.go
+++ b/internal/requestconfig/requestconfig.go
@@ -138,6 +138,7 @@ func NewRequestConfig(ctx context.Context, method string, u string, body interfa
 
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("X-Stainless-Retry-Count", "0")
+	req.Header.Set("X-Stainless-Timeout", "0")
 	for k, v := range getDefaultHeaders() {
 		req.Header.Add(k, v)
 	}
@@ -157,6 +158,18 @@ func NewRequestConfig(ctx context.Context, method string, u string, body interfa
 	if err != nil {
 		return nil, err
 	}
+
+	// This must run after `cfg.Apply(...)` above in case the request timeout gets modified. We also only
+	// apply our own logic for it if it's still "0" from above. If it's not, then it was deleted or modified
+	// by the user and we should respect that.
+	if req.Header.Get("X-Stainless-Timeout") == "0" {
+		if cfg.RequestTimeout == time.Duration(0) {
+			req.Header.Del("X-Stainless-Timeout")
+		} else {
+			req.Header.Set("X-Stainless-Timeout", strconv.Itoa(int(cfg.RequestTimeout.Seconds())))
+		}
+	}
+
 	return &cfg, nil
 }
 
diff --git a/internal/version.go b/internal/version.go
index 296d72b..985cfb5 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -2,4 +2,4 @@
 
 package internal
 
-const PackageVersion = "0.1.0-alpha.19" // x-release-please-version
+const PackageVersion = "0.1.0-alpha.20" // x-release-please-version