diff --git a/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/.conformer_randomcombine.py.swp b/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/.conformer_randomcombine.py.swp
index ec40db4c2..a3f55c1e9 100644
Binary files a/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/.conformer_randomcombine.py.swp and b/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/.conformer_randomcombine.py.swp differ
diff --git a/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/conformer_randomcombine.py b/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/conformer_randomcombine.py
index 19ef4bfd6..85e25cda3 100644
--- a/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/conformer_randomcombine.py
+++ b/egs/librispeech/ASR/pruned_transducer_stateless_gtrans/conformer_randomcombine.py
@@ -247,10 +247,12 @@ class Conformer(EncoderInterface):
                                     )
                                 )
         '''
-        x = 0
-        for enum, alpha in enumerate(self.alpha):
-            x += self.sigmoid(alpha) * layer_outputs[(enum+1)*self.group_layer_num-1]
-        x = self.layer_norm(x/self.group_num)
+
+        if self.group_num != 0:
+            x = 0
+            for enum, alpha in enumerate(self.alpha):
+                x += self.sigmoid(alpha) * layer_outputs[(enum+1)*self.group_layer_num-1]
+            x = self.layer_norm(x/self.group_num)
 
         '''
         layer_outputs = [x.permute(1, 0, 2) for x in layer_outputs]