diff --git a/dlib/server/server_http.cpp b/dlib/server/server_http.cpp
index ec5b45686..a5ac744e2 100644
--- a/dlib/server/server_http.cpp
+++ b/dlib/server/server_http.cpp
@@ -175,7 +175,7 @@ namespace dlib
         // Get the HTTP/1.1 - Ignore for now...
         read_with_limit(in, incoming.protocol);
 
-        key_value_map& incoming_headers = incoming.headers;
+        key_value_map_ci& incoming_headers = incoming.headers;
         key_value_map& cookies          = incoming.cookies;
         std::string& path               = incoming.path;
         std::string& content_type       = incoming.content_type;
@@ -333,11 +333,11 @@ namespace dlib
     {
         using namespace http_impl;
         key_value_map& new_cookies      = outgoing.cookies;
-        key_value_map& response_headers = outgoing.headers;
+        key_value_map_ci& response_headers = outgoing.headers;
 
         // only send this header if the user hasn't told us to send another kind
         bool has_content_type = false, has_location = false;
-        for(key_value_map::const_iterator ci = response_headers.begin(); ci != response_headers.end(); ++ci )
+        for(key_value_map_ci::const_iterator ci = response_headers.begin(); ci != response_headers.end(); ++ci )
         {
             if ( !has_content_type && strings_equal_ignore_case(ci->first , "content-type") )
             {
@@ -364,7 +364,7 @@ namespace dlib
         out << "HTTP/1.0 " << outgoing.http_return << " " << outgoing.http_return_status << "\r\n";
 
         // Set any new headers
-        for(key_value_map::const_iterator ci = response_headers.begin(); ci != response_headers.end(); ++ci )
+        for(key_value_map_ci::const_iterator ci = response_headers.begin(); ci != response_headers.end(); ++ci )
         {
             out << ci->first << ": " << ci->second << "\r\n";
         }
diff --git a/dlib/server/server_http.h b/dlib/server/server_http.h
index befb0a322..35335a9d1 100644
--- a/dlib/server/server_http.h
+++ b/dlib/server/server_http.h
@@ -8,6 +8,7 @@
 #include <iostream>
 #include <sstream>
 #include <string>
+#include <cctype>
 #include <map>
 #include "../logger.h"
 #include "../string.h"
@@ -39,15 +40,15 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    template <typename Key, typename Value>
-    class constmap : public std::map<Key, Value>
+    template <typename Key, typename Value, typename Comparer = std::less<Key> >
+    class constmap : public std::map<Key, Value, Comparer>
     {
     public:
         const Value& operator[](const Key& k) const
         {
             static const Value dummy = Value();
 
-            typename std::map<Key, Value>::const_iterator ci = std::map<Key, Value>::find(k);
+            typename std::map<Key, Value, Comparer>::const_iterator ci = std::map<Key, Value, Comparer>::find(k);
 
             if ( ci == this->end() )
                 return dummy;
@@ -57,10 +58,34 @@ namespace dlib
 
         Value& operator[](const Key& k)
         {
-            return std::map<Key, Value>::operator [](k);
+            return std::map<Key, Value, Comparer>::operator [](k);
         }
     };
 
+
+    class less_case_insensitive 
+    {
+    public:
+        bool operator()(const std::string& a, const std::string& b) const 
+        {
+            long i = 0;
+            while (i < a.size() && i < b.size())
+            {
+                const int cha = std::tolower(a[i]);
+                const int chb = std::tolower(b[i]);
+                if (cha < chb)
+                    return true;
+                else if (cha > chb)
+                    return false;
+                ++i;
+            }
+            if (a.size() < b.size())
+                return true;
+            else
+                return false;
+        }
+    };
+    typedef constmap< std::string, std::string, less_case_insensitive > key_value_map_ci;
     typedef constmap< std::string, std::string > key_value_map;
 
     struct incoming_things 
@@ -86,7 +111,7 @@ namespace dlib
 
         key_value_map queries;
         key_value_map cookies;
-        key_value_map headers;
+        key_value_map_ci headers;
 
         std::string foreign_ip;
         unsigned short foreign_port;
@@ -99,7 +124,7 @@ namespace dlib
         outgoing_things() : http_return(200), http_return_status("OK") { }
 
         key_value_map  cookies;
-        key_value_map  headers;
+        key_value_map_ci  headers;
         unsigned short http_return;
         std::string    http_return_status;
     };
diff --git a/dlib/server/server_http_abstract.h b/dlib/server/server_http_abstract.h
index fd3f22c0f..0bebfb61d 100644
--- a/dlib/server/server_http_abstract.h
+++ b/dlib/server/server_http_abstract.h
@@ -15,9 +15,10 @@ namespace dlib
 
     template <
         typename Key, 
-        typename Value
+        typename Value, 
+        typename Comparer = std::less<Key> 
         >
-    class constmap : public std::map<Key, Value>
+    class constmap : public std::map<Key, Value, Comparer>
     {
         /*!
             WHAT THIS OBJECT REPRESENTS
@@ -56,6 +57,10 @@ namespace dlib
     };
 
     typedef constmap<std::string, std::string> key_value_map;
+    // This version of key_value_map treats the key string as being case-insensitive.
+    // For example, a key string of "Content-Type" would access the same element as a key
+    // of "content-type".
+    typedef constmap<std::string, std::string, less_case_insensitive> key_value_map_ci;
 
 // -----------------------------------------------------------------------------------------
 
@@ -90,13 +95,13 @@ namespace dlib
         std::string protocol;
         std::string body;
 
-        key_value_map queries;
-        key_value_map cookies;
-        key_value_map headers;
+        key_value_map    queries;
+        key_value_map    cookies;
+        key_value_map_ci headers;
 
-        std::string foreign_ip;
+        std::string    foreign_ip;
         unsigned short foreign_port;
-        std::string local_ip;
+        std::string    local_ip;
         unsigned short local_port;
     };
 
@@ -119,10 +124,10 @@ namespace dlib
                 - #http_return_status == "OK"
         !*/
 
-        key_value_map  cookies;
-        key_value_map  headers;
-        unsigned short http_return;
-        std::string    http_return_status;
+        key_value_map    cookies;
+        key_value_map_ci headers;
+        unsigned short   http_return;
+        std::string      http_return_status;
     };
 
 // -----------------------------------------------------------------------------------------