diff --git a/underthesea/utils/col_external_dictionary.py b/underthesea/utils/col_external_dictionary.py
index 4a00f690..747aa359 100644
--- a/underthesea/utils/col_external_dictionary.py
+++ b/underthesea/utils/col_external_dictionary.py
@@ -27,7 +27,7 @@ def __init__(self, word, senses=[]):
 
     def __str__(self):
         return self.word + " " + ",".join([sense.tag for sense in self.senses])
-        
+
     def add_sense(self, sense):
         self.senses.append(sense)