diff --git a/files/fimplate.py b/files/fimplate.py
index 9f0a614..2d6a3f9 100755
--- a/files/fimplate.py
+++ b/files/fimplate.py
@@ -98,7 +98,7 @@ if __name__ == "__main__":
                     value = value[1:]
             l = l.replace(p[0], value)
         if options.env:
-            var_list = [m.group(0) for m in re.finditer("\${[^ ]+}", l)]
+            var_list = [m.group(0) for m in re.finditer(r"\${[^ ]+}", l)]
             for v in var_list:
                 l = l.replace(v, os.environ.get(v[:-1][2:], ""))
         sys.stdout.write(l)