diff --git a/model.py b/model.py
index 2e53bd1903a9ce1ad62f12e0e426512e5dd11a52..a2ae5d05acde85efcd62b9e2dc0662ea9c318995 100644
--- a/model.py
+++ b/model.py
@@ -178,6 +178,8 @@ class StaticGraphAdapter(object):
         optim_path = path + ".pdopt"
         optim = {p.name: p for p in filter(
             is_belong_to_optimizer, prog.list_vars())}
+        if not optim:
+            return
         # HACK this is contrived, optimizer state is not the same for
         # static/dynamic graph mode
         optim['__static_graph_only__'] = True