diff --git a/src/skUnit/Scenarios/Parsers/ChatScenarioParser.cs b/src/skUnit/Scenarios/Parsers/ChatScenarioParser.cs
index a536453..600a876 100644
--- a/src/skUnit/Scenarios/Parsers/ChatScenarioParser.cs
+++ b/src/skUnit/Scenarios/Parsers/ChatScenarioParser.cs
@@ -139,6 +139,11 @@ private static bool PackBlock(ChatScenario scenario, string newBlock, ref string
 
                 var function = key;
 
+                if (string.IsNullOrWhiteSpace(function))
+                {
+                    throw new InvalidOperationException($"CALL function name is null");
+                }
+
                 var arguments = new List<FunctionCallArgument>();
 
                 if (!string.IsNullOrWhiteSpace(contentText))