diff --git a/webserv/config/directive/SizeDirective.cpp b/webserv/config/directive/SizeDirective.cpp
index 53949a8..aad1984 100644
--- a/webserv/config/directive/SizeDirective.cpp
+++ b/webserv/config/directive/SizeDirective.cpp
@@ -25,7 +25,14 @@ void SizeDirective::parse(const std::string &value)
     {
         throw std::invalid_argument("Invalid size directive: " + value);
     }
-    value_ = std::stoul(number, &idx);
+    try
+    {
+        value_ = std::stoul(number, &idx);
+    }
+    catch (const std::exception &e)
+    {
+        throw std::invalid_argument("Invalid size directive: " + value + " - " + e.what());
+    }
     if (idx == number.size())
     {
         return;
@@ -33,15 +40,15 @@ void SizeDirective::parse(const std::string &value)
     std::string suffix = number.substr(idx);
     if (suffix == "k")
     {
-        multiplier = 1024;
+        multiplier = 1024UL;
     }
     else if (suffix == "m")
     {
-        multiplier = 1024 * 1024;
+        multiplier = 1024UL * 1024UL;
     }
     else if (suffix == "g")
     {
-        multiplier = 1024 * 1024 * 1024;
+        multiplier = 1024UL * 1024UL * 1024UL;
     }
     else
     {
diff --git a/webserv/http/HttpHeaders.cpp b/webserv/http/HttpHeaders.cpp
index 0c2fb10..1c3befa 100644
--- a/webserv/http/HttpHeaders.cpp
+++ b/webserv/http/HttpHeaders.cpp
@@ -7,7 +7,7 @@
 #include <cctype>    // for tolower
 #include <utility>   // for pair
 
-std::optional<size_t> HttpHeaders::getContentLength() const noexcept
+std::optional<size_t> HttpHeaders::getContentLength() const
 {
     const auto &value = this->get("Content-Length");
     if (value.empty())
diff --git a/webserv/http/HttpHeaders.hpp b/webserv/http/HttpHeaders.hpp
index e92e803..63e8bd8 100644
--- a/webserv/http/HttpHeaders.hpp
+++ b/webserv/http/HttpHeaders.hpp
@@ -26,7 +26,7 @@ class HttpHeaders
     void remove(const std::string &name) noexcept;
 
     [[nodiscard]] std::string toString() const noexcept;
-    [[nodiscard]] std::optional<size_t> getContentLength() const noexcept;
+    [[nodiscard]] std::optional<size_t> getContentLength() const;
     [[nodiscard]] std::optional<std::string> getContentType() const noexcept;
     [[nodiscard]] std::optional<std::string> getHost() const noexcept;
 
diff --git a/webserv/http/HttpRequest.cpp b/webserv/http/HttpRequest.cpp
index 655f22b..7cec63d 100644
--- a/webserv/http/HttpRequest.cpp
+++ b/webserv/http/HttpRequest.cpp
@@ -182,8 +182,17 @@ bool HttpRequest::parseBufferforChunkedBody()
         }
         std::string chunkSizeStr = buffer_.substr(0, pos);
         Log::debug("Chunk size string: " + chunkSizeStr);
-        size_t chunkSize = utils::stoul(chunkSizeStr, 16);
-        Log::warning("Invalid chunk size: " + chunkSizeStr);
+        size_t chunkSize = 0;
+        try
+        {
+            chunkSize = utils::stoul(chunkSizeStr, 16);
+        }
+        catch (const std::exception &e)
+        {
+            Log::warning("Invalid chunk size: " + chunkSizeStr + " - " + e.what());
+            setState(State::ParseError);
+            return false;
+        }
         if (chunkSize == 0)
         {
             setState(State::Complete); // Last chunk