diff --git a/lib/galaxy/workflow/modules.py b/lib/galaxy/workflow/modules.py
index f3843e3c916..3695334b61d 100644
--- a/lib/galaxy/workflow/modules.py
+++ b/lib/galaxy/workflow/modules.py
@@ -744,7 +744,7 @@ class InputDataModule(InputModule):
     def get_inputs(self):
         parameter_def = self._parse_state_into_dict()
         tag = parameter_def["tag"]
-        tag_source = dict(name="tag", label="Tag filter", type="text", value=tag, help="Tags to automatically filter inputs")
+        tag_source = dict(name="tag", label="Tag filter", type="text", optional="true", value=tag, help="Tags to automatically filter inputs")
         input_tag = TextToolParameter(None, tag_source)
         optional = parameter_def["optional"]
         inputs = {}