diff --git a/tools/export/makefile/__init__.py b/tools/export/makefile/__init__.py
index 3002b66a79..22ffcc8023 100644
--- a/tools/export/makefile/__init__.py
+++ b/tools/export/makefile/__init__.py
@@ -124,10 +124,10 @@ class Makefile(Exporter):
                     'to_be_compiled']:
             ctx[key] = sorted(ctx[key])
         ctx.update(self.format_flags())
+
         # Add the virtual path the the include option in the ASM flags
-        for index, flag in enumerate(ctx['asm_flags']):
-            if flag.startswith('-I'):
-                ctx['asm_flags'][index] = "-I" + ctx['vpath'][0] + "/" + ctx['asm_flags'][index][2:]
+        ctx['asm_flags'] = map(lambda item: "-I" + ctx['vpath'][0] + "/" + item[2:]
+                               if item.startswith('-I') else item, ctx['asm_flags'])
 
         for templatefile in \
             ['makefile/%s_%s.tmpl' % (self.TEMPLATE,