diff --git a/scripts/cgenerator.py b/scripts/cgenerator.py
index 732a6d2..298a774 100644
--- a/scripts/cgenerator.py
+++ b/scripts/cgenerator.py
@@ -268,7 +268,7 @@
         OutputGenerator.genGroup(self, groupinfo, groupName)
         groupElem = groupinfo.elem
 
-        expandName = re.sub(r'([0-9a-z_])([A-Z0-9][^A-Z0-9]?)',r'\1_\2',groupName).upper()
+        expandName = re.sub(r'([0-9a-z_])([A-Z0-9])',r'\1_\2',groupName).upper()
 
         expandPrefix = expandName
         expandSuffix = ''