diff --git a/RACER/preprocessing.py b/RACER/preprocessing.py
index b221970..dd272a6 100644
--- a/RACER/preprocessing.py
+++ b/RACER/preprocessing.py
@@ -43,7 +43,7 @@ def fit_transform(
         """
         X, y = pd.DataFrame(X), pd.DataFrame(y)
         if self._quantizer == "infer":
-            uniques = y.nunique()
+            uniques = y.nunique().values
             if uniques > 2:
                 self._quantizer = MOB(max_candidates=self._max_num_splits)
             else:
diff --git a/RACER/version.py b/RACER/version.py
index a82b376..72f26f5 100644
--- a/RACER/version.py
+++ b/RACER/version.py
@@ -1 +1 @@
-__version__ = "1.1.1"
+__version__ = "1.1.2"