diff --git a/common/python/nomadcore/simple_parser.py b/common/python/nomadcore/simple_parser.py
index 2ecb694fd1d2d731f2978f5ea8d3deba7210e45f..773771d4263da05e5a01a6343e69c53e6726694b 100644
--- a/common/python/nomadcore/simple_parser.py
+++ b/common/python/nomadcore/simple_parser.py
@@ -517,17 +517,17 @@ class CompiledMatcher(object):
 
     def __init__(self, matcher, possibleNexts, possibleNextsEnd, parserBuilder):
         self.matcher = matcher
-        self.groupname = [['all'],['all']]
+        self.groupname = [[],[]]
         self.startRe = re.compile(matcher.startReStr)
-        self.groupname[0].extend(str(num+1) for num in range(self.startRe.groups))
+        self.groupname[0].extend(str(num) for num in range(1, self.startRe.groups+1))
         for name, num in self.startRe.groupindex.items():
-            self.groupname[0][num] = name
+            self.groupname[0][num-1] = name
         self.endRe = None
         if matcher.endReStr:
             self.endRe = re.compile(matcher.endReStr)
-            self.groupname[1].extend(str(num+1) for num in range(self.endRe.groups))
+            self.groupname[1].extend(str(num) for num in range(1, self.endRe.groups+1))
             for name, num in self.endRe.groupindex.items():
-                self.groupname[1][num] = name
+                self.groupname[1][num-1] = name
         self.floating = matcher.floating
         currentM = matcher.superMatcher
         while currentM: