diff --git a/utils/getdeveloperlib.py b/utils/getdeveloperlib.py
index 08abcfed54..ce822320f8 100644
--- a/utils/getdeveloperlib.py
+++ b/utils/getdeveloperlib.py
@@ -251,7 +251,10 @@ def parse_developers():
                 if len(dev_files) == 0:
                     print("WARNING: '%s' doesn't match any file" % fname,
                           file=sys.stderr)
-                files += [os.path.relpath(f, brpath) for f in dev_files]
+                for f in dev_files:
+                    dev_file = os.path.relpath(f, brpath)
+                    dev_file = dev_file.replace(os.sep, '/')  # force unix sep
+                    files.append(dev_file)
             elif line == "":
                 if not name:
                     continue