diff --git a/g2p_en/g2p.py b/g2p_en/g2p.py
index 8b37659..86d1926 100644
--- a/g2p_en/g2p.py
+++ b/g2p_en/g2p.py
@@ -152,7 +152,7 @@ class G2p(object):
         text = ''.join(char for char in unicodedata.normalize('NFD', text)
                        if unicodedata.category(char) != 'Mn')  # Strip accents
         text = text.lower()
-        text = re.sub("[^ a-z'.,?!\-]", "", text)
+        text = re.sub(r"[^ a-z'.,?!\-]", "", text)
         text = text.replace("i.e.", "that is")
         text = text.replace("e.g.", "for example")