diff --git a/bitbake/lib/bb/parse/parse_py/ConfHandler.py b/bitbake/lib/bb/parse/parse_py/ConfHandler.py
index 05c627ec8b..7826dee7d3 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>:=) |
@@ -103,7 +103,7 @@ def include_single_file(parentfn, fn, lineno, data, error_out):
 # We have an issue where a UI might want to enforce particular settings such as
 # an empty DISTRO variable. If configuration files do something like assigning
 # a weak default, it turns out to be very difficult to filter out these changes,
-# particularly when the weak default might appear half way though parsing a chain 
+# particularly when the weak default might appear half way though parsing a chain
 # of configuration files. We therefore let the UIs hook into configuration file
 # parsing. This turns out to be a hard problem to solve any other way.
 confFilters = []
diff --git a/bitbake/lib/bb/tests/parse.py b/bitbake/lib/bb/tests/parse.py
index d27c7c6f15..a3165d95bd 100644
--- a/bitbake/lib/bb/tests/parse.py
+++ b/bitbake/lib/bb/tests/parse.py
@@ -222,6 +222,7 @@ VAR = " \\
     at_sign_in_var_flag = """
 A[flag@.service] = "nonet"
 B[flag@.target] = "ntb"
+C[f] = "flag"
 
 unset A[flag@.service]
 """
@@ -232,6 +233,7 @@ unset A[flag@.service]
         self.assertEqual(d.getVar("B"), None)
         self.assertEqual(d.getVarFlag("A","flag@.service"), None)
         self.assertEqual(d.getVarFlag("B","flag@.target"), "ntb")
+        self.assertEqual(d.getVarFlag("C","f"), "flag")
 
     def test_parse_invalid_at_sign_in_var_flag(self):
         invalid_at_sign = self.at_sign_in_var_flag.replace("B[f", "B[@f")