diff --git a/anndata/utils.py b/anndata/utils.py
index a561c755b..8b9724026 100644
--- a/anndata/utils.py
+++ b/anndata/utils.py
@@ -103,7 +103,7 @@ def decorator(func):
         @wraps(func)
         def new_func(*args, **kwargs):
             warnings.simplefilter('always', DeprecationWarning)  # turn off filter
-            warnings.warning(
+            warnings.warn(
                 'Use {0} instead of {1}, {1} will be removed in the future.'
                 .format(new_name, func.__name__),
                 category=DeprecationWarning,