diff --git a/client_test.go b/client_test.go
index 27d2262..eb8adac 100644
--- a/client_test.go
+++ b/client_test.go
@@ -6,6 +6,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"reflect"
 	"testing"
 	"time"
 
@@ -49,12 +50,12 @@ func TestUserAgentHeader(t *testing.T) {
 }
 
 func TestRetryAfter(t *testing.T) {
-	attempts := 0
+	retryCountHeaders := make([]string, 0)
 	client := openai.NewClient(
 		option.WithHTTPClient(&http.Client{
 			Transport: &closureTransport{
 				fn: func(req *http.Request) (*http.Response, error) {
-					attempts++
+					retryCountHeaders = append(retryCountHeaders, req.Header.Get("X-Stainless-Retry-Count"))
 					return &http.Response{
 						StatusCode: http.StatusTooManyRequests,
 						Header: http.Header{
@@ -75,8 +76,85 @@ func TestRetryAfter(t *testing.T) {
 	if err == nil || res != nil {
 		t.Error("Expected there to be a cancel error and for the response to be nil")
 	}
-	if want := 3; attempts != want {
-		t.Errorf("Expected %d attempts, got %d", want, attempts)
+
+	attempts := len(retryCountHeaders)
+	if attempts != 3 {
+		t.Errorf("Expected %d attempts, got %d", 3, attempts)
+	}
+
+	expectedRetryCountHeaders := []string{"0", "1", "2"}
+	if !reflect.DeepEqual(retryCountHeaders, expectedRetryCountHeaders) {
+		t.Errorf("Expected %v retry count headers, got %v", expectedRetryCountHeaders, retryCountHeaders)
+	}
+}
+
+func TestDeleteRetryCountHeader(t *testing.T) {
+	retryCountHeaders := make([]string, 0)
+	client := openai.NewClient(
+		option.WithHTTPClient(&http.Client{
+			Transport: &closureTransport{
+				fn: func(req *http.Request) (*http.Response, error) {
+					retryCountHeaders = append(retryCountHeaders, req.Header.Get("X-Stainless-Retry-Count"))
+					return &http.Response{
+						StatusCode: http.StatusTooManyRequests,
+						Header: http.Header{
+							http.CanonicalHeaderKey("Retry-After"): []string{"0.1"},
+						},
+					}, nil
+				},
+			},
+		}),
+		option.WithHeaderDel("X-Stainless-Retry-Count"),
+	)
+	res, err := client.Chat.Completions.New(context.Background(), openai.ChatCompletionNewParams{
+		Messages: openai.F([]openai.ChatCompletionMessageParamUnion{openai.ChatCompletionUserMessageParam{
+			Role:    openai.F(openai.ChatCompletionUserMessageParamRoleUser),
+			Content: openai.F([]openai.ChatCompletionContentPartUnionParam{openai.ChatCompletionContentPartTextParam{Text: openai.F("text"), Type: openai.F(openai.ChatCompletionContentPartTextTypeText)}}),
+		}}),
+		Model: openai.F(openai.ChatModelO1Preview),
+	})
+	if err == nil || res != nil {
+		t.Error("Expected there to be a cancel error and for the response to be nil")
+	}
+
+	expectedRetryCountHeaders := []string{"", "", ""}
+	if !reflect.DeepEqual(retryCountHeaders, expectedRetryCountHeaders) {
+		t.Errorf("Expected %v retry count headers, got %v", expectedRetryCountHeaders, retryCountHeaders)
+	}
+}
+
+func TestOverwriteRetryCountHeader(t *testing.T) {
+	retryCountHeaders := make([]string, 0)
+	client := openai.NewClient(
+		option.WithHTTPClient(&http.Client{
+			Transport: &closureTransport{
+				fn: func(req *http.Request) (*http.Response, error) {
+					retryCountHeaders = append(retryCountHeaders, req.Header.Get("X-Stainless-Retry-Count"))
+					return &http.Response{
+						StatusCode: http.StatusTooManyRequests,
+						Header: http.Header{
+							http.CanonicalHeaderKey("Retry-After"): []string{"0.1"},
+						},
+					}, nil
+				},
+			},
+		}),
+		option.WithHeader("X-Stainless-Retry-Count", "42"),
+	)
+	res, err := client.Chat.Completions.New(context.Background(), openai.ChatCompletionNewParams{
+		Messages: openai.F([]openai.ChatCompletionMessageParamUnion{openai.ChatCompletionUserMessageParam{
+			Role:    openai.F(openai.ChatCompletionUserMessageParamRoleUser),
+			Content: openai.F([]openai.ChatCompletionContentPartUnionParam{openai.ChatCompletionContentPartTextParam{Text: openai.F("text"), Type: openai.F(openai.ChatCompletionContentPartTextTypeText)}}),
+		}}),
+		Model: openai.F(openai.ChatModelO1Preview),
+	})
+	if err == nil || res != nil {
+		t.Error("Expected there to be a cancel error and for the response to be nil")
+	}
+
+	expectedRetryCountHeaders := []string{"42", "42", "42"}
+	if !reflect.DeepEqual(retryCountHeaders, expectedRetryCountHeaders) {
+		t.Errorf("Expected %v retry count headers, got %v", expectedRetryCountHeaders, retryCountHeaders)
 	}
 }
 
diff --git a/internal/requestconfig/requestconfig.go b/internal/requestconfig/requestconfig.go
index ae8e1e9..62e7956 100644
--- a/internal/requestconfig/requestconfig.go
+++ b/internal/requestconfig/requestconfig.go
@@ -137,6 +137,7 @@ 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")
 	for k, v := range getDefaultHeaders() {
 		req.Header.Add(k, v)
 	}
@@ -333,6 +334,9 @@ func (cfg *RequestConfig) Execute() (err error) {
 		handler = applyMiddleware(cfg.Middlewares[i], handler)
 	}
 
+	// Don't send the current retry count in the headers if the caller modified the header defaults.
+	shouldSendRetryCount := cfg.Request.Header.Get("X-Stainless-Retry-Count") == "0"
+
 	var res *http.Response
 	for retryCount := 0; retryCount <= cfg.MaxRetries; retryCount += 1 {
 		ctx := cfg.Request.Context()
@@ -342,7 +346,12 @@ func (cfg *RequestConfig) Execute() (err error) {
 			defer cancel()
 		}
 
-		res, err = handler(cfg.Request.Clone(ctx))
+		req := cfg.Request.Clone(ctx)
+		if shouldSendRetryCount {
+			req.Header.Set("X-Stainless-Retry-Count", strconv.Itoa(retryCount))
+		}
+
+		res, err = handler(req)
 		if ctx != nil && ctx.Err() != nil {
 			return ctx.Err()
 		}