diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index eca872d..9ae0f93 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,11 @@
 Release Notes
 =============
 
+Version 0.4.1 (21.04.2023)
+---------------------------
+
+Hotfix for pyspark import in spark criteria.
+
 Version 0.4.0 (21.04.2023)
 ---------------------------
 
diff --git a/README.rst b/README.rst
index cd962ac..e7c16dc 100644
--- a/README.rst
+++ b/README.rst
@@ -74,7 +74,7 @@ using ``pip`` extras during the installation.
 
 .. code:: bash
     
-    pip install ambrosia[pyspark]
+    pip install ambrosia[spark]
 
 .. usage
 
diff --git a/ambrosia/VERSION b/ambrosia/VERSION
index 1d0ba9e..267577d 100644
--- a/ambrosia/VERSION
+++ b/ambrosia/VERSION
@@ -1 +1 @@
-0.4.0
+0.4.1
diff --git a/ambrosia/spark_tools/stat_criteria.py b/ambrosia/spark_tools/stat_criteria.py
index 6a5c264..072ec37 100644
--- a/ambrosia/spark_tools/stat_criteria.py
+++ b/ambrosia/spark_tools/stat_criteria.py
@@ -15,10 +15,7 @@
 from typing import List, Tuple
 
 import numpy as np
-import pyspark.sql.functions as F
 import scipy.stats as sps
-from pyspark.sql.functions import col, row_number
-from pyspark.sql.window import Window
 
 import ambrosia.tools.pvalue_tools as pvalue_pkg
 import ambrosia.tools.theoretical_tools as theory_pkg
@@ -30,6 +27,8 @@
 
 if spark_installed():
     import pyspark.sql.functions as F
+    from pyspark.sql.functions import col, row_number
+    from pyspark.sql.window import Window
 
 
 class ABSparkCriterion(ABStatCriterion):
diff --git a/pyproject.toml b/pyproject.toml
index f1dd4b3..2512ef5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "Ambrosia"
-version = "0.4.0"
+version = "0.4.1"
 description = "A Python library for working with A/B tests."
 license = "Apache-2.0"
 authors = [