diff --git a/sqlparse/sql.py b/sqlparse/sql.py
index 37a3855f..19cb06f5 100644
--- a/sqlparse/sql.py
+++ b/sqlparse/sql.py
@@ -350,7 +350,6 @@ def group_tokens(self, grp_cls, start, end,
             grp = start
             grp.tokens.extend(subtokens)
             del self.tokens[start_idx + 1:end_idx]
-            grp.value = str(start)
         else:
             subtokens = self.tokens[start_idx:end_idx]
             grp = grp_cls(subtokens)
diff --git a/tests/test_parse.py b/tests/test_parse.py
index 005cc006..95f04b3f 100644
--- a/tests/test_parse.py
+++ b/tests/test_parse.py
@@ -545,7 +545,7 @@ def test_configurable_keywords():
     tokens = sqlparse.parse(sql)[0]
 
     assert list(
-        (t.ttype, t.value) for t in tokens if t.ttype not in sqlparse.tokens.Whitespace
+        (t.ttype, str(t)) for t in tokens if t.ttype not in sqlparse.tokens.Whitespace
     ) == [
         (sqlparse.tokens.Keyword.DML, "select"),
         (sqlparse.tokens.Wildcard, "*"),
@@ -569,7 +569,7 @@ def test_configurable_keywords():
     Lexer.get_default_instance().default_initialization()
 
     assert list(
-        (t.ttype, t.value) for t in tokens if t.ttype not in sqlparse.tokens.Whitespace
+        (t.ttype, str(t)) for t in tokens if t.ttype not in sqlparse.tokens.Whitespace
     ) == [
         (sqlparse.tokens.Keyword.DML, "select"),
         (sqlparse.tokens.Wildcard, "*"),