diff --git a/libs/testserver/experiments.go b/libs/testserver/experiments.go
index e35967deed..c7c3fa6c77 100644
--- a/libs/testserver/experiments.go
+++ b/libs/testserver/experiments.go
@@ -71,6 +71,8 @@ func (s *FakeWorkspace) ExperimentCreate(req Request) Response {
 		ArtifactLocation: experiment.ArtifactLocation,
 		Tags:             append(experiment.Tags, appendTags...),
 		LifecycleStage:   "active",
+		// Echo back like the real GetExperiment; omitting this immutable field triggers a spurious recreate.
+		TraceLocation: experiment.TraceLocation,
 	}
 
 	s.Experiments[experimentId] = ml.GetExperimentResponse{