diff --git a/src/Entity/CircularBuffer.cs b/src/Entity/CircularBuffer.cs
index 66e398d..0ffdbb2 100644
--- a/src/Entity/CircularBuffer.cs
+++ b/src/Entity/CircularBuffer.cs
@@ -16,7 +16,7 @@ namespace Sisk.Core.Entity;
 /// </summary>
 /// <typeparam name="T">The type of elements stored in the buffer.</typeparam>
 /// <exclude/>
-public class CircularBuffer<T> : IEnumerable<T>, IReadOnlyList<T>
+public sealed class CircularBuffer<T> : IEnumerable<T>, IReadOnlyList<T>
 {
     private T[] items;
 
diff --git a/src/Entity/HttpHeaderCollection.cs b/src/Entity/HttpHeaderCollection.cs
index 3b5d2a0..8d56eb1 100644
--- a/src/Entity/HttpHeaderCollection.cs
+++ b/src/Entity/HttpHeaderCollection.cs
@@ -8,7 +8,10 @@
 // Repository:  https://github.com/sisk-http/core
 
 using Sisk.Core.Http;
+using System.Collections;
 using System.Collections.Specialized;
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection.PortableExecutable;
 using System.Text;
 using Header = Sisk.Core.Internal.HttpKnownHeaderNames;
 
@@ -17,8 +20,11 @@ namespace Sisk.Core.Entity;
 /// <summary>
 /// Represents an collection of HTTP headers with their name and values.
 /// </summary>
-public sealed class HttpHeaderCollection : NameValueCollection
+public sealed class HttpHeaderCollection : IDictionary<string, string?>
 {
+    private List<(string headerName, string headerValue)> _headers = new();
+    internal bool isReadOnly = false;
+
     /// <summary>
     /// Create an new instance of the <see cref="HttpHeaderCollection"/> class.
     /// </summary>
@@ -31,50 +37,264 @@ public HttpHeaderCollection()
     /// headers.
     /// </summary>
     /// <param name="headers">The header collection.</param>
-    public HttpHeaderCollection(NameValueCollection headers) : base(headers)
+    public HttpHeaderCollection(NameValueCollection headers)
     {
+        foreach (string headerName in headers)
+        {
+            string[]? values = headers.GetValues(headerName);
+            if (values is not null)
+            {
+                for (int i = 0; i < values.Length; i++)
+                {
+                    string value = values[i];
+                    Add(headerName, value);
+                }
+            }
+        }
     }
 
+
     /// <inheritdoc/>
     public override string ToString()
     {
         StringBuilder sb = new StringBuilder();
-        foreach (string key in this.Keys)
+        foreach (var item in _headers)
         {
-            sb.AppendLine($"{key}: {this[key]}");
+            sb.AppendLine($"{item.headerName}: {item.headerValue}");
         }
         return sb.ToString();
     }
 
+    /// <exclude/>
+    public (string, string) this[int index]
+    {
+        get
+        {
+            var h = _headers[index];
+            return (h.headerName, h.headerValue);
+        }
+    }
+
+    /// <inheritdoc/>
+    public string? this[string headerName]
+    {
+        get
+        {
+            return string.Join(", ", GetValues(headerName));
+        }
+        set
+        {
+            Set(headerName, value);
+        }
+    }
+
+    #region Setters
+    /// <inheritdoc/>
+    public void Add(string name, string? value)
+    {
+        ThrowIfReadOnly();
+        if (value is null)
+            return;
+
+        _headers.Add((name, value));
+    }
+
+    /// <summary>
+    /// Sets the specified header to the specified value.
+    /// </summary>
+    /// <remarks>
+    /// If the header specified in the header does not exist, the Set method inserts a new
+    /// header into the list of header name/value pairs. If the header specified in header is
+    /// already present, value replaces the existing value.
+    /// </remarks>
+    /// <param name="headerName">The header name.</param>
+    /// <param name="headerValue">The header value.</param>
+    public void Set(string headerName, string? headerValue)
+    {
+        Remove(headerName);
+        Add(headerName, headerValue);
+    }
+    #endregion
+
+    #region Getters
+    /// <summary>
+    /// Gets the first headers value associated with the specified header name, or nothing it if no value
+    /// is associated with the specified header.
+    /// </summary>
+    /// <param name="name">The header name.</param>
+    public string? GetValue(string name)
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            var item = _headers[i];
+            if (string.Compare(item.headerName, name, true) == 0)
+            {
+                return item.headerValue;
+            }
+        }
+        return null;
+    }
+
+    /// <summary>
+    /// Gets all headers values associated with the specified header name.
+    /// </summary>
+    /// <param name="name">The header name.</param>
+    public IEnumerable<string> GetValues(string name)
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            var item = _headers[i];
+            if (string.Compare(item.headerName, name, true) == 0)
+            {
+                yield return item.headerValue;
+            }
+        }
+    }
+    #endregion
+
+    #region Interface methods
+
+    /// <inheritdoc/>
+    public bool ContainsKey(string key)
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            if (string.Compare(_headers[i].headerName, key, true) == 0)
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /// <inheritdoc/>
+    public bool Remove(string key)
+    {
+        ThrowIfReadOnly();
+        List<int> toRemove = new List<int>();
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            if (string.Compare(_headers[i].headerName, key, true) == 0)
+            {
+                toRemove.Add(i);
+            }
+        }
+        if (toRemove.Count > 0)
+        {
+            toRemove.Reverse();
+            for (int i = 0; i < toRemove.Count; i++)
+            {
+                _headers.RemoveAt(i);
+            }
+            return true;
+        }
+        return false;
+    }
+
+    /// <inheritdoc/>
+    public bool TryGetValue(string key, [MaybeNullWhen(false)] out string? value)
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            var item = _headers[i];
+            if (string.Compare(item.headerName, key, true) == 0)
+            {
+                value = item.headerValue;
+                return true;
+            }
+        }
+        value = default;
+        return false;
+    }
+
+    /// <inheritdoc/>
+    public void Add(KeyValuePair<string, string?> item)
+    {
+        Add(item.Key, item.Value);
+    }
+
+    /// <inheritdoc/>
+    public void Clear()
+    {
+        ThrowIfReadOnly();
+        _headers.Clear();
+    }
+
+    /// <inheritdoc/>
+    public bool Contains(KeyValuePair<string, string?> item)
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            var hitem = _headers[i];
+            if (string.Compare(hitem.headerName, item.Key, true) == 0 && hitem.headerValue.Equals(item.Value))
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /// <summary>
+    /// This method is not implemented and should not be used.
+    /// </summary>
+    [Obsolete("This method is not implemented and should not be used.")]
+    public void CopyTo(KeyValuePair<string, string?>[] array, int arrayIndex)
+    {
+        throw new NotImplementedException();
+    }
+
+    /// <inheritdoc/>
+    public bool Remove(KeyValuePair<string, string?> item)
+    {
+        return Remove(item.Key);
+    }
+
+    /// <inheritdoc/>
+    public IEnumerator<KeyValuePair<string, string?>> GetEnumerator()
+    {
+        for (int i = 0; i < _headers.Count; i++)
+        {
+            var item = _headers[i];
+            yield return new KeyValuePair<string, string?>(item.headerName, item.headerValue);
+        }
+    }
+
+    IEnumerator IEnumerable.GetEnumerator()
+    {
+        return GetEnumerator();
+    }
+    #endregion
+
+    #region Helper properties
     /// <summary>
     /// Gets or sets the value of the HTTP Accept header.
     /// </summary>
-    public string? Accept { get => base[Header.Accept]; set => base[Header.Accept] = value; }
+    public string? Accept { get => this[Header.Accept]; set => this[Header.Accept] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Accept-Charset header.
     /// </summary>
-    public string? AcceptCharset { get => base[Header.AcceptCharset]; set => base[Header.AcceptCharset] = value; }
+    public string? AcceptCharset { get => this[Header.AcceptCharset]; set => this[Header.AcceptCharset] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Accept-Encoding header.
     /// </summary>
-    public string? AcceptEncoding { get => base[Header.AcceptEncoding]; set => base[Header.AcceptEncoding] = value; }
+    public string? AcceptEncoding { get => this[Header.AcceptEncoding]; set => this[Header.AcceptEncoding] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Accept-Language header.
     /// </summary>
-    public string? AcceptLanguage { get => base[Header.AcceptLanguage]; set => base[Header.AcceptLanguage] = value; }
+    public string? AcceptLanguage { get => this[Header.AcceptLanguage]; set => this[Header.AcceptLanguage] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Accept-Patch header.
     /// </summary>
-    public string? AcceptPatch { get => base[Header.AcceptPatch]; set => base[Header.AcceptPatch] = value; }
+    public string? AcceptPatch { get => this[Header.AcceptPatch]; set => this[Header.AcceptPatch] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Accept-Ranges header.
     /// </summary>
-    public string? AcceptRanges { get => base[Header.AcceptRanges]; set => base[Header.AcceptRanges] = value; }
+    public string? AcceptRanges { get => this[Header.AcceptRanges]; set => this[Header.AcceptRanges] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Allow-Credentials header.
@@ -82,7 +302,7 @@ public override string ToString()
     /// <remarks>
     /// Note: this header can be overwritten by the current <see cref="CrossOriginResourceSharingHeaders"/> configuration.
     /// </remarks>
-    public string? AccessControlAllowCredentials { get => base[Header.AccessControlAllowCredentials]; set => base[Header.AccessControlAllowCredentials] = value; }
+    public string? AccessControlAllowCredentials { get => this[Header.AccessControlAllowCredentials]; set => this[Header.AccessControlAllowCredentials] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Allow-Headers header.
@@ -90,12 +310,12 @@ public override string ToString()
     /// <remarks>
     /// Note: this header can be overwritten by the current <see cref="CrossOriginResourceSharingHeaders"/> configuration.
     /// </remarks>
-    public string? AccessControlAllowHeaders { get => base[Header.AccessControlAllowHeaders]; set => base[Header.AccessControlAllowHeaders] = value; }
+    public string? AccessControlAllowHeaders { get => this[Header.AccessControlAllowHeaders]; set => this[Header.AccessControlAllowHeaders] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Allow-Methods header.
     /// </summary>
-    public string? AccessControlAllowMethods { get => base[Header.AccessControlAllowMethods]; set => base[Header.AccessControlAllowMethods] = value; }
+    public string? AccessControlAllowMethods { get => this[Header.AccessControlAllowMethods]; set => this[Header.AccessControlAllowMethods] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Allow-Origin header.
@@ -103,7 +323,7 @@ public override string ToString()
     /// <remarks>
     /// Note: this header can be overwritten by the current <see cref="CrossOriginResourceSharingHeaders"/> configuration.
     /// </remarks>
-    public string? AccessControlAllowOrigin { get => base[Header.AccessControlAllowOrigin]; set => base[Header.AccessControlAllowOrigin] = value; }
+    public string? AccessControlAllowOrigin { get => this[Header.AccessControlAllowOrigin]; set => this[Header.AccessControlAllowOrigin] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Expose-Headers header.
@@ -111,7 +331,7 @@ public override string ToString()
     /// <remarks>
     /// Note: this header can be overwritten by the current <see cref="CrossOriginResourceSharingHeaders"/> configuration.
     /// </remarks>
-    public string? AccessControlExposeHeaders { get => base[Header.AccessControlExposeHeaders]; set => base[Header.AccessControlExposeHeaders] = value; }
+    public string? AccessControlExposeHeaders { get => this[Header.AccessControlExposeHeaders]; set => this[Header.AccessControlExposeHeaders] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Access-Control-Max-Age header.
@@ -119,52 +339,52 @@ public override string ToString()
     /// <remarks>
     /// Note: this header can be overwritten by the current <see cref="CrossOriginResourceSharingHeaders"/> configuration.
     /// </remarks>
-    public string? AccessControlMaxAge { get => base[Header.AccessControlMaxAge]; set => base[Header.AccessControlMaxAge] = value; }
+    public string? AccessControlMaxAge { get => this[Header.AccessControlMaxAge]; set => this[Header.AccessControlMaxAge] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Age header.
     /// </summary>
-    public string? Age { get => base[Header.Age]; set => base[Header.Age] = value; }
+    public string? Age { get => this[Header.Age]; set => this[Header.Age] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Allow header.
     /// </summary>
-    public string? Allow { get => base[Header.Allow]; set => base[Header.Allow] = value; }
+    public string? Allow { get => this[Header.Allow]; set => this[Header.Allow] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Alt-Svc header.
     /// </summary>
-    public string? AltSvc { get => base[Header.AltSvc]; set => base[Header.AltSvc] = value; }
+    public string? AltSvc { get => this[Header.AltSvc]; set => this[Header.AltSvc] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Authorization header.
     /// </summary>
-    public string? Authorization { get => base[Header.Authorization]; set => base[Header.Authorization] = value; }
+    public string? Authorization { get => this[Header.Authorization]; set => this[Header.Authorization] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Cache-Control header.
     /// </summary>
-    public string? CacheControl { get => base[Header.CacheControl]; set => base[Header.CacheControl] = value; }
+    public string? CacheControl { get => this[Header.CacheControl]; set => this[Header.CacheControl] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Content-Disposition header.
     /// </summary>
-    public string? ContentDisposition { get => base[Header.ContentDisposition]; set => base[Header.ContentDisposition] = value; }
+    public string? ContentDisposition { get => this[Header.ContentDisposition]; set => this[Header.ContentDisposition] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Content-Encoding header.
     /// </summary>
-    public string? ContentEncoding { get => base[Header.ContentEncoding]; set => base[Header.ContentEncoding] = value; }
+    public string? ContentEncoding { get => this[Header.ContentEncoding]; set => this[Header.ContentEncoding] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Content-Language header.
     /// </summary>
-    public string? ContentLanguage { get => base[Header.ContentLanguage]; set => base[Header.ContentLanguage] = value; }
+    public string? ContentLanguage { get => this[Header.ContentLanguage]; set => this[Header.ContentLanguage] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Content-Range header.
     /// </summary>
-    public string? ContentRange { get => base[Header.ContentRange]; set => base[Header.ContentRange] = value; }
+    public string? ContentRange { get => this[Header.ContentRange]; set => this[Header.ContentRange] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Content-Type header.
@@ -172,7 +392,7 @@ public override string ToString()
     /// <remarks>
     /// Note: setting the value of this header, the value present in the response's <see cref="HttpContent"/> will be overwritten.
     /// </remarks>
-    public string? ContentType { get => base[Header.ContentType]; set => base[Header.ContentType] = value; }
+    public string? ContentType { get => this[Header.ContentType]; set => this[Header.ContentType] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Cookie header.
@@ -181,121 +401,117 @@ public override string ToString()
     /// Tip: use <see cref="HttpRequest.Cookies"/> property to getting cookies values from requests and
     /// <see cref="CookieHelper.SetCookie(string, string)"/> on <see cref="HttpResponse"/> to set cookies.
     /// </remarks>
-    public string? Cookie { get => base[Header.Cookie]; set => base[Header.Cookie] = value; }
+    public string? Cookie { get => this[Header.Cookie]; set => this[Header.Cookie] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Expect header.
     /// </summary>
-    public string? Expect { get => base[Header.Expect]; set => base[Header.Expect] = value; }
+    public string? Expect { get => this[Header.Expect]; set => this[Header.Expect] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Expires header.
     /// </summary>
-    public string? Expires { get => base[Header.Expires]; set => base[Header.Expires] = value; }
+    public string? Expires { get => this[Header.Expires]; set => this[Header.Expires] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Host header.
     /// </summary>
-    public string? Host { get => base[Header.Host]; set => base[Header.Host] = value; }
+    public string? Host { get => this[Header.Host]; set => this[Header.Host] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Origin header.
     /// </summary>
-    public string? Origin { get => base[Header.Origin]; set => base[Header.Origin] = value; }
+    public string? Origin { get => this[Header.Origin]; set => this[Header.Origin] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Range header.
     /// </summary>
-    public string? Range { get => base[Header.Range]; set => base[Header.Range] = value; }
+    public string? Range { get => this[Header.Range]; set => this[Header.Range] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Referer header.
     /// </summary>
-    public string? Referer { get => base[Header.Referer]; set => base[Header.Referer] = value; }
+    public string? Referer { get => this[Header.Referer]; set => this[Header.Referer] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Retry-After header.
     /// </summary>
-    public string? RetryAfter { get => base[Header.RetryAfter]; set => base[Header.RetryAfter] = value; }
+    public string? RetryAfter { get => this[Header.RetryAfter]; set => this[Header.RetryAfter] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP If-Match header.
     /// </summary>
-    public string? IfMatch { get => base[Header.IfMatch]; set => base[Header.IfMatch] = value; }
+    public string? IfMatch { get => this[Header.IfMatch]; set => this[Header.IfMatch] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP If-None-Match header.
     /// </summary>
-    public string? IfNoneMatch { get => base[Header.IfNoneMatch]; set => base[Header.IfNoneMatch] = value; }
+    public string? IfNoneMatch { get => this[Header.IfNoneMatch]; set => this[Header.IfNoneMatch] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP If-Range header.
     /// </summary>
-    public string? IfRange { get => base[Header.IfRange]; set => base[Header.IfRange] = value; }
+    public string? IfRange { get => this[Header.IfRange]; set => this[Header.IfRange] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP If-Modified-Since header.
     /// </summary>
-    public string? IfModifiedSince { get => base[Header.IfModifiedSince]; set => base[Header.IfModifiedSince] = value; }
+    public string? IfModifiedSince { get => this[Header.IfModifiedSince]; set => this[Header.IfModifiedSince] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP If-Unmodified-Since header.
     /// </summary>
-    public string? IfUnmodifiedSince { get => base[Header.IfUnmodifiedSince]; set => base[Header.IfUnmodifiedSince] = value; }
+    public string? IfUnmodifiedSince { get => this[Header.IfUnmodifiedSince]; set => this[Header.IfUnmodifiedSince] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Max-Forwards header.
     /// </summary>
-    public string? MaxForwards { get => base[Header.MaxForwards]; set => base[Header.MaxForwards] = value; }
+    public string? MaxForwards { get => this[Header.MaxForwards]; set => this[Header.MaxForwards] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Pragma header.
     /// </summary>
-    public string? Pragma { get => base[Header.Pragma]; set => base[Header.Pragma] = value; }
+    public string? Pragma { get => this[Header.Pragma]; set => this[Header.Pragma] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Proxy-Authorization header.
     /// </summary>
-    public string? ProxyAuthorization { get => base[Header.ProxyAuthorization]; set => base[Header.ProxyAuthorization] = value; }
+    public string? ProxyAuthorization { get => this[Header.ProxyAuthorization]; set => this[Header.ProxyAuthorization] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP TE header.
     /// </summary>
-    public string? TE { get => base[Header.TE]; set => base[Header.TE] = value; }
+    public string? TE { get => this[Header.TE]; set => this[Header.TE] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Trailer header.
     /// </summary>
-    public string? Trailer { get => base[Header.Trailer]; set => base[Header.Trailer] = value; }
+    public string? Trailer { get => this[Header.Trailer]; set => this[Header.Trailer] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Via header.
     /// </summary>
-    public string? Via { get => base[Header.Via]; set => base[Header.Via] = value; }
+    public string? Via { get => this[Header.Via]; set => this[Header.Via] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Set-Cookie header.
     /// </summary>
-    /// <remarks>
-    /// Tip: use <see cref="HttpRequest.Cookies"/> property to getting cookies values from requests and
-    /// <see cref="CookieHelper.SetCookie(string, string)"/> on <see cref="HttpResponse"/> to set cookies.
-    /// </remarks>
-    public string? SetCookie { get => base[Header.SetCookie]; set => base[Header.SetCookie] = value; }
+    public string? SetCookie { get => this[Header.SetCookie]; set => this[Header.SetCookie] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP User-Agent header.
     /// </summary>
-    public string? UserAgent { get => base[Header.UserAgent]; set => base[Header.UserAgent] = value; }
+    public string? UserAgent { get => this[Header.UserAgent]; set => this[Header.UserAgent] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP Vary header.
     /// </summary>
-    public string? Vary { get => base[Header.Vary]; set => base[Header.Vary] = value; }
+    public string? Vary { get => this[Header.Vary]; set => this[Header.Vary] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP WWW-Authenticate header.
     /// </summary>
-    public string? WWWAuthenticate { get => base[Header.WWWAuthenticate]; set => base[Header.WWWAuthenticate] = value; }
+    public string? WWWAuthenticate { get => this[Header.WWWAuthenticate]; set => this[Header.WWWAuthenticate] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP X-Forwarded-For header.
@@ -303,7 +519,7 @@ public override string ToString()
     /// <remarks>
     /// Tip: enable the <see cref="HttpServerConfiguration.ResolveForwardedOriginAddress"/> property to obtain the user client proxied IP throught <see cref="HttpRequest.RemoteAddress"/>.
     /// </remarks>
-    public string? XForwardedFor { get => base[Header.XForwardedFor]; set => base[Header.XForwardedFor] = value; }
+    public string? XForwardedFor { get => this[Header.XForwardedFor]; set => this[Header.XForwardedFor] = value; }
 
     /// <summary>
     /// Gets or sets the value of the HTTP X-Forwarded-Host header.
@@ -311,6 +527,46 @@ public override string ToString()
     /// <remarks>
     /// Tip: enable the <see cref="HttpServerConfiguration.ResolveForwardedOriginHost"/> property to obtain the client requested host throught <see cref="HttpRequest.Host"/>.
     /// </remarks>
-    public string? XForwardedHost { get => base[Header.XForwardedHost]; set => base[Header.XForwardedHost] = value; }
+    public string? XForwardedHost { get => this[Header.XForwardedHost]; set => this[Header.XForwardedHost] = value; }
 
+    /// <inheritdoc/>
+    public ICollection<string> Keys
+    {
+        get
+        {
+            List<string> headerNames = new List<string>(_headers.Count);
+            for (int i = 0; i < _headers.Count; i++)
+            {
+                headerNames.Add(_headers[i].headerName);
+            }
+            return headerNames;
+        }
+    }
+
+    /// <inheritdoc/>
+    public ICollection<string?> Values
+    {
+        get
+        {
+            List<string?> headerValues = new List<string?>(_headers.Count);
+            for (int i = 0; i < _headers.Count; i++)
+            {
+                headerValues.Add(_headers[i].headerValue);
+            }
+            return headerValues;
+        }
+    }
+
+    /// <inheritdoc/>
+    public int Count => _headers.Count;
+
+    /// <inheritdoc/>
+    public bool IsReadOnly => isReadOnly;
+    #endregion
+
+    void ThrowIfReadOnly()
+    {
+        if (isReadOnly)
+            throw new InvalidOperationException(SR.Collection_ReadOnly);
+    }
 }
diff --git a/src/Entity/MultipartObject.cs b/src/Entity/MultipartObject.cs
index 947957a..1c93b55 100644
--- a/src/Entity/MultipartObject.cs
+++ b/src/Entity/MultipartObject.cs
@@ -81,7 +81,7 @@ public MultipartObjectCommonFormat GetCommonFileFormat()
             {
                 Span<byte> len8 = ContentBytes.AsSpan(0, 8);
 
-                if (len8.SequenceEqual(new byte[] { 137, 80, 78, 71, 13, 10, 26, 10 }))
+                if (len8.SequenceEqual(MultipartObjectCommonFormatByteMark.PNG))
                 {
                     return MultipartObjectCommonFormat.PNG;
                 }
@@ -90,39 +90,40 @@ public MultipartObjectCommonFormat GetCommonFileFormat()
             {
                 Span<byte> len4 = ContentBytes.AsSpan(0, 4);
 
-                if (len4.SequenceEqual(new byte[] { (byte)'R', (byte)'I', (byte)'F', (byte)'F' }))
+                if (len4.SequenceEqual(MultipartObjectCommonFormatByteMark.WEBP))
                 {
                     return MultipartObjectCommonFormat.WEBP;
                 }
-                else if (len4.SequenceEqual(new byte[] { 0x25, 0x50, 0x44, 0x46 }))
+                else if (len4.SequenceEqual(MultipartObjectCommonFormatByteMark.PDF))
                 {
                     return MultipartObjectCommonFormat.PDF;
                 }
+                else if (len4.SequenceEqual(MultipartObjectCommonFormatByteMark.TIFF))
+                {
+                    return MultipartObjectCommonFormat.TIFF;
+                }
             }
             if (byteLen >= 3)
             {
                 Span<byte> len3 = ContentBytes.AsSpan(0, 3);
 
-                if (len3.SequenceEqual(new byte[] { 0xFF, 0xD8, 0xFF }))
+                if (len3.SequenceEqual(MultipartObjectCommonFormatByteMark.JPEG))
                 {
                     return MultipartObjectCommonFormat.JPEG;
                 }
-                else if (len3.SequenceEqual(new byte[] { 73, 73, 42 }))
-                {
-                    return MultipartObjectCommonFormat.TIFF;
-                }
-                else if (len3.SequenceEqual(new byte[] { 77, 77, 42 }))
+                else if (len3.SequenceEqual(MultipartObjectCommonFormatByteMark.GIF))
                 {
-                    return MultipartObjectCommonFormat.TIFF;
+                    return MultipartObjectCommonFormat.GIF;
                 }
-                else if (len3.SequenceEqual(new byte[] { 0x42, 0x4D }))
+            }
+            if (byteLen >= 2)
+            {
+                Span<byte> len2 = ContentBytes.AsSpan(0, 2);
+
+                if (len2.SequenceEqual(MultipartObjectCommonFormatByteMark.BMP))
                 {
                     return MultipartObjectCommonFormat.BMP;
                 }
-                else if (len3.SequenceEqual(new byte[] { 0x47, 0x46, 0x49 }))
-                {
-                    return MultipartObjectCommonFormat.GIF;
-                }
             }
 
             return MultipartObjectCommonFormat.Unknown;
@@ -130,7 +131,7 @@ public MultipartObjectCommonFormat GetCommonFileFormat()
 
         internal MultipartObject(NameValueCollection headers, string? filename, string name, byte[]? body, Encoding encoding)
         {
-            Headers = new HttpHeaderCollection(headers);
+            Headers = new HttpHeaderCollection(headers) { isReadOnly = true };
             Filename = filename;
             Name = name;
             ContentBytes = body ?? Array.Empty<byte>();
@@ -314,50 +315,4 @@ bool Equals(byte[] source, byte[] separator, int index)
             return new MultipartFormCollection(outputObjects);
         }
     }
-
-    /// <summary>
-    /// Represents an image format for Multipart objects.
-    /// </summary>
-    public enum MultipartObjectCommonFormat
-    {
-        /// <summary>
-        /// Represents that the object is not a recognized image.
-        /// </summary>
-        Unknown = 0,
-
-        /// <summary>
-        /// Represents an JPEG/JPG image.
-        /// </summary>
-        JPEG = 100,
-
-        /// <summary>
-        /// Represents an GIF image.
-        /// </summary>
-        GIF = 101,
-
-        /// <summary>
-        /// Represents an PNG image.
-        /// </summary>
-        PNG = 102,
-
-        /// <summary>
-        /// Represents an TIFF image.
-        /// </summary>
-        TIFF = 103,
-
-        /// <summary>
-        /// Represents an bitmap image.
-        /// </summary>
-        BMP = 104,
-
-        /// <summary>
-        /// Represents an WebP image.
-        /// </summary>
-        WEBP = 105,
-
-        /// <summary>
-        /// Represents an PDF file.
-        /// </summary>
-        PDF = 200
-    }
 }
diff --git a/src/Entity/MultipartObjectCommonFormat.cs b/src/Entity/MultipartObjectCommonFormat.cs
new file mode 100644
index 0000000..b191652
--- /dev/null
+++ b/src/Entity/MultipartObjectCommonFormat.cs
@@ -0,0 +1,56 @@
+// The Sisk Framework source code
+// Copyright (c) 2023 PROJECT PRINCIPIUM
+//
+// The code below is licensed under the MIT license as
+// of the date of its publication, available at
+//
+// File name:   MultipartObjectCommonFormat.cs
+// Repository:  https://github.com/sisk-http/core
+
+namespace Sisk.Core.Entity;
+
+/// <summary>
+/// Represents an image format for Multipart objects.
+/// </summary>
+public enum MultipartObjectCommonFormat
+{
+    /// <summary>
+    /// Represents that the object is not a recognized image.
+    /// </summary>
+    Unknown = 0,
+
+    /// <summary>
+    /// Represents an JPEG/JPG image.
+    /// </summary>
+    JPEG = 100,
+
+    /// <summary>
+    /// Represents an GIF image.
+    /// </summary>
+    GIF = 101,
+
+    /// <summary>
+    /// Represents an PNG image.
+    /// </summary>
+    PNG = 102,
+
+    /// <summary>
+    /// Represents an TIFF image.
+    /// </summary>
+    TIFF = 103,
+
+    /// <summary>
+    /// Represents an bitmap image.
+    /// </summary>
+    BMP = 104,
+
+    /// <summary>
+    /// Represents an WebP image.
+    /// </summary>
+    WEBP = 105,
+
+    /// <summary>
+    /// Represents an PDF file.
+    /// </summary>
+    PDF = 200
+}
diff --git a/src/Entity/MultipartObjectCommonFormatByteMark.cs b/src/Entity/MultipartObjectCommonFormatByteMark.cs
new file mode 100644
index 0000000..59f2d9e
--- /dev/null
+++ b/src/Entity/MultipartObjectCommonFormatByteMark.cs
@@ -0,0 +1,25 @@
+// The Sisk Framework source code
+// Copyright (c) 2023 PROJECT PRINCIPIUM
+//
+// The code below is licensed under the MIT license as
+// of the date of its publication, available at
+//
+// File name:   MultipartObjectCommonFormatByteMark.cs
+// Repository:  https://github.com/sisk-http/core
+
+namespace Sisk.Core.Entity;
+
+internal static class MultipartObjectCommonFormatByteMark
+{
+    public static readonly byte[] PNG = new byte[] { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A };
+
+    public static readonly byte[] PDF = new byte[] { 0x25, 0x50, 0x44, 0x46 };
+    public static readonly byte[] WEBP = new byte[] { 0x52, 0x49, 0x46, 0x46 };
+    public static readonly byte[] TIFF = new byte[] { 0x4D, 0x4D, 0x00, 0x2A };
+    public static readonly byte[] WEBM = new byte[] { 0x1A, 0x45, 0xDF, 0xA3 };
+
+    public static readonly byte[] JPEG = new byte[] { 0xFF, 0xD8, 0xFF };
+    public static readonly byte[] GIF = new byte[] { 0x47, 0x46, 0x49 };
+
+    public static readonly byte[] BMP = new byte[] { 0x42, 0x4D };
+}
diff --git a/src/Entity/StringValueCollection.cs b/src/Entity/StringValueCollection.cs
index 573ac23..7247623 100644
--- a/src/Entity/StringValueCollection.cs
+++ b/src/Entity/StringValueCollection.cs
@@ -74,9 +74,9 @@ public NameValueCollection AsNameValueCollection()
     {
         NameValueCollection n = new NameValueCollection();
 
-        foreach (string key in items.Keys)
+        foreach (var item in items)
         {
-            n.Add(key, items[key]);
+            n.Add(item.Key, item.Value);
         }
 
         return n;
diff --git a/src/Http/Handlers/HttpServerHandlerRepository.cs b/src/Http/Handlers/HttpServerHandlerRepository.cs
index 9687c4a..8878479 100644
--- a/src/Http/Handlers/HttpServerHandlerRepository.cs
+++ b/src/Http/Handlers/HttpServerHandlerRepository.cs
@@ -16,7 +16,7 @@ namespace Sisk.Core.Http.Handlers;
 internal class HttpServerHandlerRepository
 {
     private readonly HttpServer parent;
-    private readonly List<HttpServerHandler> handlers = new List<HttpServerHandler>();
+    private readonly List<HttpServerHandler> handlers = new List<HttpServerHandler>(20);
     internal readonly DefaultHttpServerHandler _default = new DefaultHttpServerHandler();
 
     public HttpServerHandlerRepository(HttpServer parent)
diff --git a/src/Http/HttpContext.cs b/src/Http/HttpContext.cs
index 9046f73..c4774ad 100644
--- a/src/Http/HttpContext.cs
+++ b/src/Http/HttpContext.cs
@@ -7,6 +7,7 @@
 // File name:   HttpContext.cs
 // Repository:  https://github.com/sisk-http/core
 
+using Sisk.Core.Entity;
 using Sisk.Core.Routing;
 using System.Collections.Specialized;
 
@@ -21,7 +22,7 @@ public sealed class HttpContext
         /// Gets or sets an <see cref="NameValueCollection"/> indicating HTTP headers which
         /// will overwrite headers set by CORS, router response or request handlers.
         /// </summary>
-        public NameValueCollection OverrideHeaders { get; set; } = new NameValueCollection();
+        public HttpHeaderCollection OverrideHeaders { get; set; } = new HttpHeaderCollection();
 
         /// <summary>
         /// Gets the <see cref="ListeningHost"/> instance of this HTTP context.
diff --git a/src/Http/HttpRequest.cs b/src/Http/HttpRequest.cs
index 1982129..8014034 100644
--- a/src/Http/HttpRequest.cs
+++ b/src/Http/HttpRequest.cs
@@ -151,8 +151,10 @@ public HttpHeaderCollection Headers
                     }
                     else
                     {
-                        headers = new HttpHeaderCollection(listenerRequest.Headers);
+                        headers = new HttpHeaderCollection((WebHeaderCollection)listenerRequest.Headers);
                     }
+
+                    headers.isReadOnly = true;
                 }
 
                 return headers;
@@ -367,10 +369,9 @@ public string GetRawHttpRequest(bool includeBody = true, bool appendExtraInfo =
                 sb.AppendLine($":request-id: {RequestId}");
                 sb.AppendLine($":request-proto: {(IsSecure ? "https" : "http")}");
             }
-            foreach (string hName in Headers)
+            foreach (var header in Headers)
             {
-                string hValue = Headers[hName]!;
-                sb.AppendLine($"{hName}: {hValue}");
+                sb.AppendLine($"{header.Key}: {header.Value}");
             }
             sb.AppendLine();
 
diff --git a/src/Http/HttpResponse.cs b/src/Http/HttpResponse.cs
index 41928c9..48cedee 100644
--- a/src/Http/HttpResponse.cs
+++ b/src/Http/HttpResponse.cs
@@ -102,10 +102,9 @@ public string GetRawHttpResponse(bool includeBody = true)
         {
             StringBuilder sb = new StringBuilder();
             sb.AppendLine($"HTTP/1.1 {StatusInformation}");
-            foreach (string header in Headers)
+            foreach (var header in Headers)
             {
-                sb.Append(header + ": ");
-                sb.Append(Headers[header]);
+                sb.Append($"{header.Key}: {header.Value}");
                 sb.Append('\n');
             }
             if (Content?.Headers is not null)
@@ -167,7 +166,7 @@ public HttpResponse WithContent(HttpContent content)
         /// <returns>The self <see cref="HttpResponse"/> object.</returns>
         public HttpResponse WithHeader(string headerKey, string headerValue)
         {
-            Headers.Set(headerKey, headerValue);
+            Headers.Add(headerKey, headerValue);
             return this;
         }
 
@@ -179,7 +178,7 @@ public HttpResponse WithHeader(string headerKey, string headerValue)
         public HttpResponse WithHeader(NameValueCollection headers)
         {
             foreach (string key in headers.Keys)
-                Headers.Set(key, headers[key]);
+                Headers.Add(key, headers[key]);
             return this;
         }
 
@@ -286,7 +285,7 @@ public HttpResponse(HttpStatusCode status, HttpContent? content)
         /// <inheritdoc/>
         protected override void SetCookieHeader(String name, String value)
         {
-            Headers.Set(name, value);
+            Headers.Add(name, value);
         }
     }
 }
diff --git a/src/Http/HttpServer__Core.cs b/src/Http/HttpServer__Core.cs
index 19298d5..705eb6f 100644
--- a/src/Http/HttpServer__Core.cs
+++ b/src/Http/HttpServer__Core.cs
@@ -10,7 +10,6 @@
 using Sisk.Core.Entity;
 using Sisk.Core.Internal;
 using Sisk.Core.Routing;
-using System.Collections.Specialized;
 using System.Diagnostics;
 using System.Net;
 using System.Runtime.CompilerServices;
@@ -308,23 +307,25 @@ private void ProcessRequest(HttpListenerContext context)
             #endregion
 
             #region Step 4 - Response computing
-            NameValueCollection resHeaders = new NameValueCollection
-            {
-                response.Headers
-            };
+            HttpHeaderCollection resHeaders = response.Headers;
+            HttpHeaderCollection overrideHeaders = srContext.OverrideHeaders;
 
             long? responseContentLength = response.Content?.Headers.ContentLength;
-            if (srContext?.OverrideHeaders.Count > 0) resHeaders.Add(srContext.OverrideHeaders);
+            if (overrideHeaders.Count > 0)
+            {
+                for (int i = 0; i < overrideHeaders.Count; i++)
+                {
+                    var overridingHeader = overrideHeaders[i];
+                    resHeaders.Set(overridingHeader.Item1, overridingHeader.Item2);
+                }
+            }
 
             for (int i = 0; i < resHeaders.Count; i++)
             {
-                string? incameHeader = resHeaders.Keys[i];
-                if (string.IsNullOrEmpty(incameHeader)) continue;
-
-                string? value = resHeaders[incameHeader];
-                if (string.IsNullOrEmpty(value)) continue;
+                (string, string) incameHeader = resHeaders[i];
+                if (string.IsNullOrEmpty(incameHeader.Item1)) continue;
 
-                baseResponse.Headers[incameHeader] = value;
+                baseResponse.Headers.Add(incameHeader.Item1, incameHeader.Item2);
             }
 
             _debugState = "sent_headers";
diff --git a/src/Internal/LoggingConstants.cs b/src/Internal/LoggingConstants.cs
index 566b191..3d8309a 100644
--- a/src/Internal/LoggingConstants.cs
+++ b/src/Internal/LoggingConstants.cs
@@ -22,7 +22,7 @@ internal class LoggingFormatter
         readonly DateTime d;
         readonly Uri? bReqUri;
         readonly IPAddress? bReqIpAddr;
-        readonly NameValueCollection? reqHeaders;
+        readonly IDictionary<string, string?>? reqHeaders;
         readonly int bResStatusCode;
         readonly string? bResStatusDescr;
         readonly string bReqMethod;
@@ -34,7 +34,7 @@ public LoggingFormatter(
             HttpServerExecutionResult res,
             DateTime d, Uri? bReqUri,
             IPAddress? bReqIpAddr,
-            NameValueCollection? reqHeaders,
+            IDictionary<string, string?>? reqHeaders,
             int bResStatusCode,
             string? bResStatusDescr,
             long execTime,
diff --git a/src/Internal/SR.cs b/src/Internal/SR.cs
index 93bda01..e908585 100644
--- a/src/Internal/SR.cs
+++ b/src/Internal/SR.cs
@@ -89,6 +89,8 @@ static partial class SR
     public const string ValueItem_ValueNull = "The value \"{0}\" contained at this {1} is null or it's undefined.";
     public const string ValueItem_CastException = "Cannot cast the value \"{0}\" at parameter {1} into an {2}.";
 
+    public const string Collection_ReadOnly = "Cannot insert items to this collection as it is read-only.";
+
     public static string Format(string format, params object?[] items)
     {
         return String.Format(format, items);
diff --git a/src/Sisk.Core.csproj b/src/Sisk.Core.csproj
index 571d861..ee5b789 100644
--- a/src/Sisk.Core.csproj
+++ b/src/Sisk.Core.csproj
@@ -31,7 +31,7 @@
 
 		<AssemblyVersion>1.0.0.0</AssemblyVersion>
 		<FileVersion>1.0.0.0</FileVersion>
-		<Version>1.0.0.0-rc4</Version>
+		<Version>1.0.0.0-rc5</Version>
 
 		<PackageLicenseFile>LICENSE.txt</PackageLicenseFile>
 		<SignAssembly>False</SignAssembly>