diff --git a/CMakeLists.txt b/CMakeLists.txt
index e26cfb7..a57980a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.14)
-project(oatpp-authkit VERSION 0.2.0 LANGUAGES CXX)
+project(oatpp-authkit VERSION 0.2.1 LANGUAGES CXX)
 
 # Header-only interface library — no compilation, just an include path and
 # a CMake config package so consumers do:
diff --git a/include/oatpp-authkit/handler/JsonErrorHandler.hpp b/include/oatpp-authkit/handler/JsonErrorHandler.hpp
index 04a1f4e..d2ce7f1 100644
--- a/include/oatpp-authkit/handler/JsonErrorHandler.hpp
+++ b/include/oatpp-authkit/handler/JsonErrorHandler.hpp
@@ -4,6 +4,8 @@
 #include "oatpp/web/server/handler/ErrorHandler.hpp"
 #include "oatpp/web/protocol/http/outgoing/ResponseFactory.hpp"
 
+namespace oatpp_authkit {
+
 /**
  * @brief Custom error handler that returns JSON error responses.
  *
@@ -63,4 +65,6 @@ private:
     }
 };
 
+} // namespace oatpp_authkit
+
 #endif // HANDLER_JSON_ERROR_HANDLER_HPP
diff --git a/include/oatpp-authkit/interceptor/BodySizeLimitInterceptor.hpp b/include/oatpp-authkit/interceptor/BodySizeLimitInterceptor.hpp
index 47cdd34..9189e76 100644
--- a/include/oatpp-authkit/interceptor/BodySizeLimitInterceptor.hpp
+++ b/include/oatpp-authkit/interceptor/BodySizeLimitInterceptor.hpp
@@ -4,6 +4,8 @@
 #include "oatpp/web/server/interceptor/RequestInterceptor.hpp"
 #include "oatpp/web/protocol/http/outgoing/ResponseFactory.hpp"
 
+namespace oatpp_authkit {
+
 /**
  * @brief Request interceptor that rejects requests exceeding a body size limit.
  *
@@ -40,4 +42,6 @@ public:
     }
 };
 
+} // namespace oatpp_authkit
+
 #endif
diff --git a/include/oatpp-authkit/interceptor/SecurityHeadersInterceptor.hpp b/include/oatpp-authkit/interceptor/SecurityHeadersInterceptor.hpp
index ddeb5a5..0e3a4cc 100644
--- a/include/oatpp-authkit/interceptor/SecurityHeadersInterceptor.hpp
+++ b/include/oatpp-authkit/interceptor/SecurityHeadersInterceptor.hpp
@@ -3,6 +3,8 @@
 
 #include "oatpp/web/server/interceptor/ResponseInterceptor.hpp"
 
+namespace oatpp_authkit {
+
 /**
  * @brief Response interceptor that adds standard security headers to all responses.
  *
@@ -36,4 +38,6 @@ public:
     }
 };
 
+} // namespace oatpp_authkit
+
 #endif
diff --git a/include/oatpp-authkit/util/RateLimiter.hpp b/include/oatpp-authkit/util/RateLimiter.hpp
index ace4555..4a8bad4 100644
--- a/include/oatpp-authkit/util/RateLimiter.hpp
+++ b/include/oatpp-authkit/util/RateLimiter.hpp
@@ -6,6 +6,8 @@
 #include <string>
 #include <unordered_map>
 
+namespace oatpp_authkit {
+
 /**
  * @brief Per-key token bucket rate limiter.
  *
@@ -82,4 +84,6 @@ private:
     std::unordered_map<std::string, Bucket> m_buckets;
 };
 
+} // namespace oatpp_authkit
+
 #endif // UTIL_RATE_LIMITER_HPP