diff --git a/volia/masseffect.py b/volia/masseffect.py
index 0163eea..c3c4615 100644
--- a/volia/masseffect.py
+++ b/volia/masseffect.py
@@ -99,8 +99,9 @@ def utt2sub(file: str, outfile: str):
     with open(outfile, "w") as of:
         key_2_subkeys = {}
         for subkey in keys:
-            key = subkey.replace(" ", "").replace("\n", "").split("_")[:-1]
-            key_2_subkeys[key] = []
+            key = "_".join(subkey.replace(" ", "").replace("\n", "").split("_")[:-1])
+            if key not in key_2_subkeys:
+                key_2_subkeys[key] = []
             key_2_subkeys[key].append(subkey)
 
         for key in key_2_subkeys:
@@ -114,7 +115,7 @@ def sub2utt(file: str, outfile: str):
 
     with open(outfile, "w") as of:
         for subkey in keys:
-            key = subkey.replace(" ", "").replace("\n", "").split("_")[:-1]
+            key = "_".join(subkey.replace(" ", "").replace("\n", "").split("_")[:-1])
             of.write(f"{subkey} {key}\n")