diff --git a/lib/galaxy/model/__init__.py b/lib/galaxy/model/__init__.py
index 3a4e269dedb..dc6ce037105 100644
--- a/lib/galaxy/model/__init__.py
+++ b/lib/galaxy/model/__init__.py
@@ -4440,6 +4440,9 @@ class WorkflowInvocation(UsesCreateAndUpdateTime, Dictifiable, RepresentById):
         return [wid for wid in query.all()]
 
     def add_output(self, workflow_output, step, output_object):
+        if step.type == 'parameter_input':
+            # TODO: these should be properly tracked.
+            return
         if output_object.history_content_type == "dataset":
             output_assoc = WorkflowInvocationOutputDatasetAssociation()
             output_assoc.workflow_invocation = self