diff --git a/src/Runner.Worker/ExecutionContext.cs b/src/Runner.Worker/ExecutionContext.cs
index 1cfcb0956..182274b81 100644
--- a/src/Runner.Worker/ExecutionContext.cs
+++ b/src/Runner.Worker/ExecutionContext.cs
@@ -270,6 +270,12 @@ namespace GitHub.Runner.Worker
         {
             Trace.Entering();
 
+            // TODO: Null out old, non-json refNames only if a FF is set.
+            if (refName != null && !refName.StartsWith("{"))
+            {
+                refName = null;
+            }
+
             var child = new ExecutionContext();
             child.Initialize(HostContext);
             child.ScopeName = scopeName;
@@ -873,7 +879,9 @@ namespace GitHub.Runner.Worker
             }
 
             var newGuid = Guid.NewGuid();
-            return CreateChild(newGuid, displayName, refName ?? newGuid.ToString("N"), null, null, intraActionState, _childTimelineRecordOrder - Root.PostJobSteps.Count);
+
+            // TODO: Check feature flag here, conditionally set refName to newGuid.ToString("N").
+            return CreateChild(newGuid, displayName, refName, null, null, intraActionState, _childTimelineRecordOrder - Root.PostJobSteps.Count);
         }
     }
 
diff --git a/src/Runner.Worker/IStepExtensions.cs b/src/Runner.Worker/IStepExtensions.cs
index 404698276..0d55fced3 100644
--- a/src/Runner.Worker/IStepExtensions.cs
+++ b/src/Runner.Worker/IStepExtensions.cs
@@ -6,17 +6,26 @@ namespace GitHub.Runner.Worker
   {
     public static string GetRefName(this IStep step, string defaultRefName = null)
     {
-      if (step is JobExtensionRunner extensionRunner && extensionRunner.RepositoryRef != null)
+      // TODO: Really check a feature flag.
+      if (s_featureFlagEnabled)
       {
-        return JsonConvert.SerializeObject(extensionRunner.RepositoryRef);
-      }
+        if (step is JobExtensionRunner extensionRunner && extensionRunner.RepositoryRef != null)
+        {
+          return JsonConvert.SerializeObject(extensionRunner.RepositoryRef);
+        }
 
-      if (step is IActionRunner actionRunner && actionRunner.Action?.Reference != null)
-      {
-        return JsonConvert.SerializeObject(actionRunner.Action.Reference);
+        if (step is IActionRunner actionRunner && actionRunner.Action?.Reference != null)
+        {
+          return JsonConvert.SerializeObject(actionRunner.Action.Reference);
+        }
+
+        // RefName should always be valid json or null.
+        return null;
       }
 
       return defaultRefName;
     }
+
+    private static bool s_featureFlagEnabled = true;
   }
 }
\ No newline at end of file