diff --git a/graphenebase/base58.py b/graphenebase/base58.py
index a62522e8..f3300807 100644
--- a/graphenebase/base58.py
+++ b/graphenebase/base58.py
@@ -64,6 +64,8 @@ def __format__(self, _format) :
             return _format.upper() + str(self)
         elif _format.lower() == "muse" :
             return _format.upper() + str(self)
+        elif _format.lower() == "test" :
+            return _format.upper() + str(self)
         else :
             raise Exception("Format %s unkown." % _format)