diff --git a/api/core/workflow/nodes/tool/tool_node.py b/api/core/workflow/nodes/tool/tool_node.py
index 969b1c241e52a..87bfa5beae880 100644
--- a/api/core/workflow/nodes/tool/tool_node.py
+++ b/api/core/workflow/nodes/tool/tool_node.py
@@ -118,6 +118,7 @@ def _generate_parameters(
         for parameter_name in node_data.tool_parameters:
             parameter = tool_parameters_dictionary.get(parameter_name)
             if not parameter:
+                result[parameter_name] = None
                 continue
             if parameter.type == ToolParameter.ToolParameterType.FILE:
                 result[parameter_name] = [