diff --git a/Sources/Swollama/GenerateRequest.swift b/Sources/Swollama/GenerateRequest.swift
index 1be18cc..77d1b45 100644
--- a/Sources/Swollama/GenerateRequest.swift
+++ b/Sources/Swollama/GenerateRequest.swift
@@ -63,7 +63,7 @@ public struct GenerateRequest: Codable, Sendable {
 }
 
 /// Response format options
-public enum ResponseFormat: String, Codable, Sendable {
+public enum ResponseFormat: String, Codable {
     case json
 }
 
@@ -108,7 +108,7 @@ public struct ChatMessage: Codable, Sendable {
 }
 
 /// Available message roles
-public enum MessageRole: String, Codable, Sendable {
+public enum MessageRole: String, Codable {
     case system
     case user
     case assistant
diff --git a/Sources/Swollama/OllamaClient.swift b/Sources/Swollama/OllamaClient.swift
index fa54236..0e42a03 100644
--- a/Sources/Swollama/OllamaClient.swift
+++ b/Sources/Swollama/OllamaClient.swift
@@ -1,7 +1,7 @@
 import Foundation
 
 /// A client for interacting with the Ollama API
-public actor OllamaClient: @preconcurrency OllamaProtocol {
+public actor OllamaClient: OllamaProtocol {
     public let baseURL: URL
     public let configuration: OllamaConfiguration
     
@@ -44,7 +44,7 @@ public actor OllamaClient: @preconcurrency OllamaProtocol {
         request.httpMethod = method
         request.httpBody = body
         
-        if body != nil {
+        if let body = body {
             request.setValue("application/json", forHTTPHeaderField: "Content-Type")
         }