diff --git a/Slon/Api/V1/Statuses.HC b/Slon/Api/V1/Statuses.HC
index 207832d..96831ed 100644
--- a/Slon/Api/V1/Statuses.HC
+++ b/Slon/Api/V1/Statuses.HC
@@ -57,7 +57,7 @@ U0 @slon_api_v1_statuses_post(SlonHttpSession* session)
         SLON_AUTH_ACCOUNT_ID
 
         Bool idempotency_key_already_seen = FALSE;
-        U8* idempotency_key = @slon_http_request_header(session, "idempotency-key");
+        U8* idempotency_key = session->header("idempotency-key");
         if (StrLen(idempotency_key) > 0 && db->o("idempotency_keys")->@(idempotency_key)) {
             idempotency_key_already_seen = TRUE;
         }
diff --git a/Slon/Endpoints/Get/ActivityPub.HC b/Slon/Endpoints/Get/ActivityPub.HC
index 974f2a2..110c7bf 100644
--- a/Slon/Endpoints/Get/ActivityPub.HC
+++ b/Slon/Endpoints/Get/ActivityPub.HC
@@ -1,4 +1,4 @@
-if (String.BeginsWith("/users/", @slon_http_request_path(session)) && String.EndsWith("json", @slon_http_request_header(session, "accept"))) {
+if (String.BeginsWith("/users/", @slon_http_request_path(session)) && String.EndsWith("json", session->header("accept"))) {
     @slon_activitypub_users_get(session);
     return;
 }
diff --git a/Slon/Http/AdminServer.HC b/Slon/Http/AdminServer.HC
index 1c2c0d2..0cb5b57 100644
--- a/Slon/Http/AdminServer.HC
+++ b/Slon/Http/AdminServer.HC
@@ -285,7 +285,7 @@ U0 @slon_admin_server_get(SlonHttpSession* session)
     if (!db->@("setup")) {
         if (StrICmp("/", @slon_http_request_path(session))) {
             session->status(302);
-            @slon_http_set_header(session, "Location", "/");
+            session->header("Location", "/");
         } else {
             @slon_http_send_html_file(session, "M:/Slon/Static/html/admin/setup_instance.html");
         }
@@ -335,7 +335,7 @@ U0 @slon_admin_setup_instance(SlonHttpSession* session)
 
 U0 @slon_admin_server_post(SlonHttpSession* session)
 {
-    if (StrFind("json", @slon_http_request_header(session, "content-type")) > 0) {
+    if (StrFind("json", session->header("content-type")) > 0) {
         @slon_http_parse_request_as_json(session);
     }
 
@@ -402,8 +402,8 @@ U0 @slon_admin_http_task(TcpSocket* s)
     }
 
     // If we have a content-length header, consume until we receive all the data, then set request->data pointer and size
-    if (StrLen(@slon_http_request_header(session, "content-length"))) {
-        I64 content_length = Str2I64(@slon_http_request_header(session, "content-length"));
+    if (StrLen(session->header("content-length"))) {
+        I64 content_length = Str2I64(session->header("content-length"));
         while (session->request->buffer->data + session->request->buffer->size - session->request->data < content_length)
             @slon_http_receive(session);
     }
diff --git a/Slon/Http/LocalServer.HC b/Slon/Http/LocalServer.HC
index 371c9cf..06ccece 100644
--- a/Slon/Http/LocalServer.HC
+++ b/Slon/Http/LocalServer.HC
@@ -164,7 +164,7 @@ U0 @slon_local_server_get(SlonHttpSession* session)
         if (IsDir(scratch_buffer)) {
             session->status(301);
             StrPrint(scratch_buffer, "%s/", path);
-            @slon_http_set_header(session, "Location", scratch_buffer);
+            session->header("Location", scratch_buffer);
         } else {
             @slon_local_server_send_file(session, scratch_buffer);
         }
@@ -214,8 +214,8 @@ U0 @slon_local_http_task(TcpSocket* s)
     }
 
     // If we have a content-length header, consume until we receive all the data, then set request->data pointer and size
-    if (StrLen(@slon_http_request_header(session, "content-length"))) {
-        I64 content_length = Str2I64(@slon_http_request_header(session, "content-length"));
+    if (StrLen(session->header("content-length"))) {
+        I64 content_length = Str2I64(session->header("content-length"));
         while (session->request->buffer->data + session->request->buffer->size - session->request->data < content_length)
             @slon_http_receive(session);
     }
diff --git a/Slon/Http/Server.HC b/Slon/Http/Server.HC
index 0462483..0a76689 100644
--- a/Slon/Http/Server.HC
+++ b/Slon/Http/Server.HC
@@ -43,6 +43,7 @@ U0 @slon_http_free_session(SlonHttpSession* session)
     @slon_http_free_response(session, session->response);
     @slon_http_free_request(session, session->request);
     I64 bytes_used = session->bytes_used - MSize2(session);
+    Free(session->header);
     Free(session->status);
     Free(session);
     if (bytes_used) {
@@ -84,6 +85,23 @@ SlonHttpSession* @slon_http_init_session(TcpSocket* s)
     a += 0x10;
     MemSetI64(a, session, 1);
 
+    // Create a copy of function and patch header
+    code_size = MSize(&@slon_session_header_wrapper_function);
+    session->header = CAlloc(code_size, adam_task->code_heap);
+    MemCpy(session->header, &@slon_session_header_wrapper_function, code_size);
+
+    a = session->header;
+    a += 0x16;
+    MemSetI64(a, session, 1);
+
+    a = session->header;
+    a += 0x26;
+    @patch_call_rel32(a, &@slon_http_request_header);
+
+    a = session->header;
+    a += 0x31;
+    @patch_call_rel32(a, &@slon_http_set_header);
+
     return session;
 }
 
@@ -215,8 +233,8 @@ slon_http_parse_request_headers:
 
 U0 @slon_http_authorize(SlonHttpSession* session)
 {
-    if (StrLen(@slon_http_request_header(session, "authorization"))) {
-        U8* access_token = StrFind(" ", @slon_http_request_header(session, "authorization")) + 1;
+    if (StrLen(session->header("authorization"))) {
+        U8* access_token = StrFind(" ", session->header("authorization")) + 1;
         session->auth = db->o("oauth")->o("tokens")->@(access_token);
     }
 }
@@ -283,7 +301,7 @@ U8* @slon_http_json_string_from_multipart_form_data(SlonHttpSession* session, U8
     String.Append(json_string, "{");
     U8* multipart_form_data_copy = @slon_strnew(session, multipart_form_data);
 
-    U8* boundary = StrFind("boundary=", @slon_http_request_header(session, "content-type")) + 9;
+    U8* boundary = StrFind("boundary=", session->header("content-type")) + 9;
     // Strip begin double-quotes and ending CRLF, double-quotes
     while (boundary[0] == '"')
         boundary++;
@@ -430,13 +448,13 @@ U0 @slon_http_handle_get_request(SlonHttpSession* session)
 
 U0 @slon_http_handle_patch_request(SlonHttpSession* session)
 {
-    if (StrFind("json", @slon_http_request_header(session, "content-type")) > 0) {
+    if (StrFind("json", session->header("content-type")) > 0) {
         @slon_http_parse_request_as_json(session);
     }
-    if (String.BeginsWith("application/x-www-form-urlencoded", @slon_http_request_header(session, "content-type"))) {
+    if (String.BeginsWith("application/x-www-form-urlencoded", session->header("content-type"))) {
         @slon_http_parse_request_as_form_urlencoded(session);
     }
-    if (String.BeginsWith("multipart/form-data", @slon_http_request_header(session, "content-type"))) {
+    if (String.BeginsWith("multipart/form-data", session->header("content-type"))) {
         @slon_http_parse_request_as_multipart_form_data(session);
     }
 
@@ -453,17 +471,17 @@ U0 @slon_http_handle_patch_request(SlonHttpSession* session)
 
 U0 @slon_http_handle_post_request(SlonHttpSession* session)
 {
-    if (StrFind("json", @slon_http_request_header(session, "content-type")) > 0) {
+    if (StrFind("json", session->header("content-type")) > 0) {
         @slon_http_parse_request_as_json(session);
     }
-    if (String.BeginsWith("application/x-www-form-urlencoded", @slon_http_request_header(session, "content-type"))) {
+    if (String.BeginsWith("application/x-www-form-urlencoded", session->header("content-type"))) {
         @slon_http_parse_request_as_form_urlencoded(session);
     }
-    if (String.BeginsWith("multipart/form-data", @slon_http_request_header(session, "content-type"))) {
+    if (String.BeginsWith("multipart/form-data", session->header("content-type"))) {
         @slon_http_parse_request_as_multipart_form_data(session);
     }
     // Workaround for IceCubesApp: https://github.com/Dimillian/IceCubesApp/issues/2235
-    if (!StrLen(@slon_http_request_header(session, "content-type")) && @slon_http_request_has_query_string(session)) {
+    if (!StrLen(session->header("content-type")) && @slon_http_request_has_query_string(session)) {
         @slon_http_parse_query_string(session);
     }
 
@@ -533,8 +551,8 @@ U0 @slon_http_task(TcpSocket* s)
     //@slon_http_debug_print_request(session, FALSE);
 
     // If we have a content-length header, consume until we receive all the data, then set request->data pointer and size
-    if (StrLen(@slon_http_request_header(session, "content-length"))) {
-        I64 content_length = Str2I64(@slon_http_request_header(session, "content-length"));
+    if (StrLen(session->header("content-length"))) {
+        I64 content_length = Str2I64(session->header("content-length"));
         while (session->request->buffer->data + session->request->buffer->size - session->request->data < content_length)
             @slon_http_receive(session);
     }
diff --git a/Slon/Modules/ActivityPub.HC b/Slon/Modules/ActivityPub.HC
index fb31b22..70fe831 100644
--- a/Slon/Modules/ActivityPub.HC
+++ b/Slon/Modules/ActivityPub.HC
@@ -13,19 +13,19 @@ Bool @slon_activitypub_http_signature_is_valid(SlonHttpSession* session)
     no_warn scratch_buffer;
 
     // 1. Check that we have a signature and digest
-    if (!StrLen(@slon_http_request_header(session, "signature")) || !StrLen(@slon_http_request_header(session, "digest"))) {
+    if (!StrLen(session->header("signature")) || !StrLen(session->header("digest"))) {
         AdamLog("[verify_signature] no signature or digest header present\n");
         return FALSE;
     }
 
     // 2. Check that digest 1) is SHA-256 and 2) matches content
-    U8* request_digest = @slon_http_request_header(session, "digest");
+    U8* request_digest = session->header("digest");
     if (!(String.BeginsWith("SHA-256", request_digest) || String.BeginsWith("sha-256", request_digest))) {
         AdamLog("[verify_signature] digest is not SHA-256\n");
         return FALSE;
     }
     request_digest = StrFind("=", request_digest) + 1;
-    I64 content_length = Str2I64(@slon_http_request_header(session, "content-length"));
+    I64 content_length = Str2I64(session->header("content-length"));
     if (!content_length) {
         AdamLog("[verify_signature] content-length is 0\n");
         return FALSE;
@@ -44,7 +44,7 @@ Bool @slon_activitypub_http_signature_is_valid(SlonHttpSession* session)
     }
 
     // Parse values from Signature header
-    U8* signature_header = @slon_http_request_header(session, "signature");
+    U8* signature_header = session->header("signature");
     I64 signature_fragment_count = 0;
     U8** signature_fragments = String.Split(signature_header, ',', &signature_fragment_count);
 
@@ -192,7 +192,7 @@ Bool @slon_activitypub_http_signature_is_valid(SlonHttpSession* session)
     U8** headers_split = String.Split(headers, ' ', &headers_split_count);
     i = 0;
     while (i < headers_split_count) {
-        sig_string_alloc_length += StrLen(@slon_http_request_header(session, headers_split[i]));
+        sig_string_alloc_length += StrLen(session->header(headers_split[i]));
         ++i;
     }
     sig_string_alloc_length += StrLen(@slon_http_request_verb(session));
@@ -209,7 +209,7 @@ Bool @slon_activitypub_http_signature_is_valid(SlonHttpSession* session)
         if (!StrCmp("(request-target)", headers_split[i])) {
             String.Append(sig_string, "(request-target): %s %s", "post", @slon_http_request_path(session));
         } else {
-            String.Append(sig_string, "%s: %s", headers_split[i], @slon_http_request_header(session, headers_split[i]));
+            String.Append(sig_string, "%s: %s", headers_split[i], session->header(headers_split[i]));
         }
         ++i;
         if (i < headers_split_count) {
diff --git a/Slon/Modules/Http.HC b/Slon/Modules/Http.HC
index 4767f47..73e8d0b 100644
--- a/Slon/Modules/Http.HC
+++ b/Slon/Modules/Http.HC
@@ -63,6 +63,7 @@ class SlonHttpSession {
     JsonObject* auth;
     U8* actor_for_key_id;
 
+    U8* (*header)(U8* key, U8* value = NULL);
     I64 (*status)(I64 code = NULL);
 };
 
@@ -148,12 +149,16 @@ JsonObject* @slon_http_request_json(SlonHttpSession* session)
 
 U0 @slon_http_set_header(SlonHttpSession* session, U8* key, U8* value)
 {
-    Json.Set(session->response->headers, key, value, JSON_STRING);
+    if (!StrICmp(value, "")) {
+        Json.Unset(session->response->headers, key);
+    } else {
+        Json.Set(session->response->headers, key, value, JSON_STRING);
+    }
 }
 
 U0 @slon_http_set_content_type(SlonHttpSession* session, U8* value)
 {
-    @slon_http_set_header(session, "content-type", value);
+    session->header("content-type", value);
 }
 
 U0 @slon_http_send_ap_json(SlonHttpSession* session, U64 json)
@@ -263,3 +268,13 @@ I64 @slon_session_status_wrapper_function(I64 code)
     }
     return session->response->status_code;
 }
+
+U8* @slon_session_header_wrapper_function(U8* key, U8* value = NULL)
+{
+    SlonHttpSession* session = SLON_WRAPPER_MAGIC_NUMBER;
+    if (!value) {
+        return @slon_http_request_header(session, key);
+    }
+    @slon_http_set_header(session, key, value);
+    return value;
+}