diff --git a/slim/prune.py b/slim/prune.py
index 8d73febf96..1108f85b9d 100644
--- a/slim/prune.py
+++ b/slim/prune.py
@@ -82,7 +82,7 @@ def parse_args():
 
 
 def eval_fn(net, eval_dataset, num_workers):
-    miou, _ = evaluate(
+    miou, _, _, _, _ = evaluate(
         net, eval_dataset, num_workers=num_workers, print_detail=False)
     return miou