diff --git a/lib/galaxy/managers/hdas.py b/lib/galaxy/managers/hdas.py
index 2f71fe37cc7..931f167b63f 100644
--- a/lib/galaxy/managers/hdas.py
+++ b/lib/galaxy/managers/hdas.py
@@ -327,7 +327,7 @@ class HDASerializer(  # datasets._UnflattenedMetadataDatasetAssociationSerialize
             'file_path'     : self._remap_from( 'file_name' ),
 
             'resubmitted'   : lambda i, k, **c: self.hda_manager.has_been_resubmitted( i ),
-            'creating_job'  : lambda i, k, **c: self.app.security.encode_id(i.creating_job.id),
+            'creating_job'  : self.serialize_creating_job,
 
             'display_apps'  : self.serialize_display_apps,
             'display_types' : self.serialize_old_display_applications,
@@ -433,6 +433,12 @@ class HDASerializer(  # datasets._UnflattenedMetadataDatasetAssociationSerialize
         }
         return urls
 
+    def serialize_creating_job( self, hda, key, **context ):
+        if hda.creating_job:
+            self.app.security.encode_id(hda.creating_job.id),
+        else:
+            return None
+
 
 class HDADeserializer( datasets.DatasetAssociationDeserializer,
                        taggable.TaggableDeserializerMixin,
diff --git a/lib/galaxy/webapps/galaxy/api/jobs.py b/lib/galaxy/webapps/galaxy/api/jobs.py
index fe3b35d9959..a7b8f64203b 100644
--- a/lib/galaxy/webapps/galaxy/api/jobs.py
+++ b/lib/galaxy/webapps/galaxy/api/jobs.py
@@ -190,7 +190,7 @@ class JobController( BaseAPIController, UsesLibraryMixinItems ):
     def build_for_rerun( self, trans, id, **kwd ):
         """
         * GET /api/jobs/{job_id}/build_for_rerun
-            returns a tool input/param template preopoulated with this job's
+            returns a tool input/param template prepopulated with this job's
             information, suitable for rerunning or rendering parameters of the
             job.