diff --git a/generator/generator.lua b/generator/generator.lua
index e68498f..2796776 100644
--- a/generator/generator.lua
+++ b/generator/generator.lua
@@ -13,7 +13,7 @@ local CPRE,CTEST
 --get implementations
 local implementations = {}
 for i=3,#script_args do
-    if script_args[i]:match("^[-/]") then
+    if script_args[i]:match(COMPILER == cl and "^/" or "^%-") then
         local key, value = script_args[i]:match("^(.+)=(.+)$")
         if key and value then
             CFLAGS = CFLAGS .. " " .. key .. "=\"" .. value:gsub("\"", "\\\"") .. "\"";