diff --git a/bitbake/lib/bb/parse/parse_py/ConfHandler.py b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
index 7826dee7d3..27665443dd 100644
--- a/bitbake/lib/bb/parse/parse_py/ConfHandler.py
+++ b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
@@ -21,7 +21,7 @@ __config_regexp__  = re.compile( r"""
     ^
     (?P<exp>export\s+)?
     (?P<var>[a-zA-Z0-9\-_+.${}/~:]+?)
-    (\[(?P<flag>[a-zA-Z0-9\-_+.][a-zA-Z0-9\-_+.@]*)\])?
+    (\[(?P<flag>[a-zA-Z0-9\-_+.][a-zA-Z0-9\-_+.@/]*)\])?
 
     \s* (
         (?P<colon>:=) |