diff --git a/library/server/wsf/router/wsf_method_helper.e b/library/server/wsf/router/wsf_method_helper.e
index 899e28b0..61783af8 100644
--- a/library/server/wsf/router/wsf_method_helper.e
+++ b/library/server/wsf/router/wsf_method_helper.e
@@ -204,7 +204,7 @@ feature -- Content negotiation
 				else
 					if attached l_lang.language_type as l_language_type then
 						h.put_content_language (l_language_type)
-						req.set_execution_variable ("NEGOTIATED_LANGUAGE", l_language_type)
+						req.set_execution_variable (a_handler.Negotiated_language_execution_variable, l_language_type)
 					end
 					l_charsets := a_handler.charsets_supported (req)
 					l_charset := l_conneg.charset_preference (l_charsets, req.http_accept_charset)
@@ -217,11 +217,11 @@ feature -- Content negotiation
 						if attached l_media.media_type as l_media_type then
 							if attached l_charset.character_type as l_character_type  then
 								h.put_content_type (l_media_type + "; charset=" + l_character_type)
-								req.set_execution_variable ("NEGOTIATED_CHARSET", l_charset)
+								req.set_execution_variable (a_handler.Negotiated_charset_execution_variable, l_charset)
 							else
 								h.put_content_type (l_media_type)
 							end
-							req.set_execution_variable ("NEGOTIATED_MEDIA_TYPE", l_media_type)
+							req.set_execution_variable (a_handler.Negotiated_media_type_execution_variable, l_media_type)
 						end
 						l_encodings := a_handler.encodings_supported (req)
 						l_encoding := l_conneg.encoding_preference (l_encodings, req.http_accept_encoding)
@@ -233,15 +233,15 @@ feature -- Content negotiation
 						else
 							if attached l_encoding.compression_type as l_compression_type then
 								h.put_content_encoding (l_compression_type)
-								req.set_execution_variable ("NEGOTIATED_ENCODING", l_compression_type)
+								req.set_execution_variable (a_handler.Negotiated_encoding_execution_variable, l_compression_type)
 							end
 						end
 					end
 				end
 			end
-			req.set_execution_variable ("NEGOTIATED_HTTP_HEADER", h)
+			req.set_execution_variable (a_handler.Negotiated_http_header_execution_variable, h)
 		ensure
-			header_attached: attached {HTTP_HEADER} req.execution_variable ("NEGOTIATED_HTTP_HEADER")
+			header_attached: attached {HTTP_HEADER} req.execution_variable (a_handler.Negotiated_http_header_execution_variable)
 		end
 
 feature {NONE} -- Implementation
diff --git a/library/server/wsf/router/wsf_skeleton_handler.e b/library/server/wsf/router/wsf_skeleton_handler.e
index b246af4c..780034ee 100644
--- a/library/server/wsf/router/wsf_skeleton_handler.e
+++ b/library/server/wsf/router/wsf_skeleton_handler.e
@@ -26,6 +26,26 @@ inherit
 
 	WSF_SELF_DOCUMENTED_HANDLER
 
+feature -- Execution variables
+
+	Negotiated_language_execution_variable: STRING = "NEGOTIATED_LANGUAGE"
+			-- Execution variable set by framework
+		
+	Negotiated_charset_execution_variable: STRING = "NEGOTIATED_CHARSET"
+			-- Execution variable set by framework
+
+	Negotiated_media_type_execution_variable: STRING = "NEGOTIATED_MEDIA_TYPE"
+			-- Execution variable set by framework
+
+	Negotiated_encoding_execution_variable: STRING = "NEGOTIATED_ENCODING"
+			-- Execution variable set by framework
+
+	Negotiated_http_header_execution_variable: STRING = "NEGOTIATED_HTTP_HEADER"
+			-- Execution variable set by framework
+
+	Request_entity_execution_variable: STRING = "REQUEST_ENTITY"
+			-- Execution variable set by framework
+
 feature -- Access
 
 	is_chunking (req: WSF_REQUEST): BOOLEAN
@@ -295,7 +315,7 @@ feature -- GET/HEAD content
 feature -- PUT/POST
 
 	read_entity (req: WSF_REQUEST)
-			-- Read request body and set as `req.execution_variable ("REQUEST_ENTITY")'.
+			-- Read request body and set as `req.execution_variable (Request_entity_execution_variable)'.
 		require
 			req_attached: req /= Void
 		local
@@ -304,7 +324,7 @@ feature -- PUT/POST
 			create l_body.make_empty
 			req.read_input_data_into (l_body)
 			if not l_body.is_empty then
-				req.set_execution_variable ("REQUEST_ENTITY", l_body)
+				req.set_execution_variable (Request_entity_execution_variable, l_body)
 			end
 		end