diff --git a/test.py b/test.py
index 8c01134..7a35fd8 100755
--- a/test.py
+++ b/test.py
@@ -126,7 +126,10 @@ def validation(model, criterion, evaluation_loader, converter, opt):
 
             if pred == gt:
                 n_correct += 1
-            norm_ED += edit_distance(pred, gt) / len(gt)
+            if len(gt) == 0:
+                norm_ED += 1
+            else:
+                norm_ED += edit_distance(pred, gt) / len(gt)
 
     accuracy = n_correct / float(length_of_data) * 100