Added missing import.

1 files changed, 1 insertions, 0 deletions

diff --git a/bs4/css.py b/bs4/css.py
index 197bfaf..245ac60 100644
--- a/bs4/css.py
+++ b/bs4/css.py
@@ -1,5 +1,6 @@
 """Integration code for CSS selectors using Soup Sieve (pypi: soupsieve)."""
 
+import warnings
 try:
     import soupsieve
 except ImportError as e: