diff --git a/tools/program.py b/tools/program.py
index dd8037e473..53994b8560 100755
--- a/tools/program.py
+++ b/tools/program.py
@@ -171,7 +171,7 @@ def to_float32(preds):
             else:
                 preds[k] = paddle.to_tensor(preds[k], dtype='float32')
     else:
-        preds[k] = paddle.to_tensor(preds[k], dtype='float32')
+        preds = paddle.to_tensor(preds, dtype='float32')
     return preds