diff --git a/nlpcraft/src/test/scala/org/apache/nlpcraft/model/intent/idl/compiler/functions/NCIdlFunctionsStat.scala b/nlpcraft/src/test/scala/org/apache/nlpcraft/model/intent/idl/compiler/functions/NCIdlFunctionsStat.scala
index b9dabb2..9513dc3 100644
--- a/nlpcraft/src/test/scala/org/apache/nlpcraft/model/intent/idl/compiler/functions/NCIdlFunctionsStat.scala
+++ b/nlpcraft/src/test/scala/org/apache/nlpcraft/model/intent/idl/compiler/functions/NCIdlFunctionsStat.scala
@@ -45,6 +45,8 @@
             "avg(list(1.2, 2.2, 3.2)) == 2.2",
             "avg(list(1, 2.2, 3.1)) == 2.1",
             "stdev(list(1, 2.2, 3.1)) > 0",
+            "stdev(list(1, 2, 3)) > 0",
             "stdev(list(0.0, 0.0, 0.0)) == 0.0",
+            "stdev(list(0, 0, 0)) == 0.0",
         )
 }