diff --git a/tests/performance/single_fixed_string_groupby.xml b/tests/performance/single_fixed_string_groupby.xml
index 6bf5821707f..8e166a124ff 100644
--- a/tests/performance/single_fixed_string_groupby.xml
+++ b/tests/performance/single_fixed_string_groupby.xml
@@ -10,8 +10,8 @@
         INSERT INTO perf_lc_fixed_str_groupby SELECT ('number key ' || toString(number % 400)) AS a, ('number key ' || toString(number % 20)) AS b FROM numbers(30000000)
     </fill_query>
 
-    <query short="1">SELECT count() FROM perf_lc_fixed_str_groupby GROUP BY a</query>
-    <query short="1">SELECT count() FROM perf_lc_fixed_str_groupby GROUP BY b</query>
+    <query short="1">SELECT count() FROM perf_lc_fixed_str_groupby GROUP BY a FORMAT Null</query>
+    <query short="1">SELECT count() FROM perf_lc_fixed_str_groupby GROUP BY b FORMAT Null</query>
 
     <drop_query>DROP TABLE IF EXISTS perf_lc_fixed_str_groupby</drop_query>
 </test>