diff --git a/google/internal/externalaccount/sts_exchange.go b/google/internal/externalaccount/sts_exchange.go
index c2f0626..1bcd661 100644
--- a/google/internal/externalaccount/sts_exchange.go
+++ b/google/internal/externalaccount/sts_exchange.go
@@ -31,8 +31,8 @@ func ExchangeToken(ctx context.Context, endpoint string, request *STSTokenExchan
 	if err != nil {
 		return nil, fmt.Errorf("oauth2/google: failed to marshal additional options: %v", err)
 	}
-
 	data.Set("options", string(opts))
+
 	authentication.InjectAuthentication(data, headers)
 	encodedData := data.Encode()
 
@@ -57,14 +57,13 @@ func ExchangeToken(ctx context.Context, endpoint string, request *STSTokenExchan
 
 	bodyJson := json.NewDecoder(io.LimitReader(resp.Body, 1<<20))
 	var stsResp STSTokenExchangeResponse
-	for bodyJson.More() {
-		err = bodyJson.Decode(&stsResp)
-		if err != nil {
-			return nil, fmt.Errorf("oauth2/google: failed to unmarshal response body from Secure Token Server: %v", err)
+	err = bodyJson.Decode(&stsResp)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: failed to unmarshal response body from Secure Token Server: %v", err)
 
-		}
 	}
 
+
 	return &stsResp, nil
 }