diff --git a/ChangeLog b/ChangeLog
index e8f1b4b..9814f1d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+2015-03-11  Manuel Guesdon <mguesdon@orange-concept.com>
+	* GSWeb/GSWConstants.m
+	  downcase Header keys
 2015-03-11  Manuel Guesdon <mguesdon@orange-concept.com>
 	* GSWeb/GSWHTTPIO.m
 	  force header keys to lowercase
diff --git a/GSWeb/GSWConstants.m b/GSWeb/GSWConstants.m
index 8993852..5b93cf7 100644
--- a/GSWeb/GSWConstants.m
+++ b/GSWeb/GSWConstants.m
@@ -147,19 +147,19 @@ NSString* GSWHTTPHeader_AdaptorStats[2] = { @"x-gsweb-adaptorstats", @"x-webobje
 
 NSString* GSWHTTPHeader_MethodPost=@"POST";
 NSString* GSWHTTPHeader_MethodGet=@"GET";
-NSString* GSWHTTPHeader_AcceptLanguage=@"Accept-Language";
-NSString* GSWHTTPHeader_AcceptEncoding=@"Accept-Encoding";
-NSString* GSWHTTPHeader_ContentDisposition=@"Content-Disposition";
-NSString* GSWHTTPHeader_ContentEncoding=@"Content-Encoding";
-NSString* GSWHTTPHeader_ContentType=@"Content-Type";
+NSString* GSWHTTPHeader_AcceptLanguage=@"accept-language";
+NSString* GSWHTTPHeader_AcceptEncoding=@"accept-encoding";
+NSString* GSWHTTPHeader_ContentDisposition=@"content-disposition";
+NSString* GSWHTTPHeader_ContentEncoding=@"content-encoding";
+NSString* GSWHTTPHeader_ContentType=@"content-type";
 NSString* GSWHTTPHeader_FormURLEncoded=@"application/x-www-form-urlencoded";
-NSString* GSWHTTPHeader_Location=@"Location";
+NSString* GSWHTTPHeader_Location=@"location";
 NSString* GSWHTTPHeader_MultipartFormData=@"multipart/form-data";
 NSString* GSWHTTPHeader_MimeType_TextPlain=@"text/plain";
-NSString* GSWHTTPHeader_UserAgent=@"User-Agent";
-NSString* GSWHTTPHeader_Referer=@"Referer";
+NSString* GSWHTTPHeader_UserAgent=@"user-agent";
+NSString* GSWHTTPHeader_Referer=@"referer";
 
-NSString* GSWHTTPHeader_ContentLength=@"Content-Length";
+NSString* GSWHTTPHeader_ContentLength=@"content-length";
 
 NSString* GSWHTTPHeader_Response_OK=@"OK";