diff --git a/src/requirements/ContractState/ContractStateForm.tsx b/src/requirements/ContractState/ContractStateForm.tsx
index b907c42ed4..b7c4b1c06c 100644
--- a/src/requirements/ContractState/ContractStateForm.tsx
+++ b/src/requirements/ContractState/ContractStateForm.tsx
@@ -291,6 +291,10 @@ const ContractStateForm = ({ baseFieldPath }: RequirementFormProps) => {
       >
         <FormLabel>Expected output:</FormLabel>
 
+        <Text fontSize="sm" color="gray.500">
+          Output param indexes start from 0, i.e. the first output param index is 0
+        </Text>
+
         {shouldRenderSimpleInputs ? (
           <Controller
             name={`${baseFieldPath}.data.resultIndex`}