diff --git a/ibis/backends/tests/test_window.py b/ibis/backends/tests/test_window.py
index 80c48db3415b..f395cc8d7007 100644
--- a/ibis/backends/tests/test_window.py
+++ b/ibis/backends/tests/test_window.py
@@ -158,6 +158,7 @@ def calc_zscore(s):
                     "duckdb",
                     'impala',
                     'postgres',
+                    'mssql',
                     'mysql',
                     'sqlite',
                     'snowflake',
@@ -190,6 +191,7 @@ def calc_zscore(s):
                     "duckdb",
                     'impala',
                     'postgres',
+                    'mssql',
                     'mysql',
                     'sqlite',
                     'snowflake',