diff --git a/docs/faq.rst b/docs/faq.rst
index 3acccbe5..e7597f66 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -98,6 +98,9 @@ Currently this adds the support for elaborated type specifiers.
 \_\_va_list_tag and other hidden declarations (f1)
 --------------------------------------------------
 
+!!! This flag has been removed from pygccxml > 2.6
+We will now always remove these declarations
+
 When parsing with CastXML, the XML tree can contain declarations named
 ``__va_list_tag``. If the compiler is llvm 3.9,  ``__NSConstantString_tag``
 and ``__NSConstantString`` declarations may also be present.
diff --git a/src/pygccxml/parser/scanner.py b/src/pygccxml/parser/scanner.py
index d11814d9..160c308a 100644
--- a/src/pygccxml/parser/scanner.py
+++ b/src/pygccxml/parser/scanner.py
@@ -197,6 +197,15 @@ def __init__(self, xml_file, decl_factory, config, *args):
             "__vr_offs",
         ]
 
+        # With CastXML and clang some __va_list_tag declarations are
+        # present in the tree
+        # With llvm 3.9 there is a __NSConstantString(_tag) in the tree
+        self.__declarations_to_skip = [
+            "__va_list_tag",
+            "__NSConstantString_tag",
+            "__NSConstantString"
+        ]
+
         self.__xml_generator_from_xml_file = None
 
     @property
@@ -297,21 +306,10 @@ def startElement(self, name, attrs):
             self.__read_access(attrs)
             element_id = attrs.get(XML_AN_ID)
 
-            # With CastXML and clang some __va_list_tag declarations are
-            # present in the tree: we do not want to have these in the tree.
-            # With llvm 3.9 there is a __NSConstantString(_tag) in the tree
-            # We hide these declarations by default
-            rm1 = "f1" not in self.config.flags
-            names = [
-                "__va_list_tag",
-                "__NSConstantString_tag",
-                "__NSConstantString"]
-
             if isinstance(obj, declarations.declaration_t):
 
-                if rm1 and str(obj.name) in names:
+                if obj.name in self.__declarations_to_skip:
                     return
-
                 self.__update_membership(attrs)
                 self.__declarations[element_id] = obj
                 if not isinstance(obj, declarations.namespace_t):
diff --git a/tests/test_va_list_tag_removal.py b/tests/test_va_list_tag_removal.py
deleted file mode 100644
index 2a675665..00000000
--- a/tests/test_va_list_tag_removal.py
+++ /dev/null
@@ -1,116 +0,0 @@
-# Copyright 2014-2017 Insight Software Consortium.
-# Copyright 2004-2009 Roman Yakovenko.
-# Distributed under the Boost Software License, Version 1.0.
-# See http://www.boost.org/LICENSE_1_0.txt
-
-import os
-import platform
-
-from . import autoconfig
-
-from pygccxml import parser
-from pygccxml import declarations
-
-
-"""
-Test the remove__va_list_tag option
-
-With CastXML and clang some __va_list_tag declarations are present in the
-tree. This options allows to remove them when parsing the xml file.
-
-"""
-
-
-__code = os.linesep.join(['struct a{};'])
-known_typedefs = ["__int128_t", "__uint128_t", "__builtin_va_list"]
-known_typedefs_llvm39 = known_typedefs + ["__builtin_ms_va_list"]
-known_classes = ["a"]
-known_classes_llvm39 = known_classes + ["__NSConstantString_tag"]
-
-
-def test_keep_va_list_tag():
-
-    if platform.system() == 'Windows':
-        return True
-
-    config = autoconfig.cxx_parsers_cfg.config.clone()
-
-    config.flags = ["f1"]
-    src_reader = parser.source_reader_t(config)
-    decls = declarations.make_flatten(src_reader.read_string(__code))
-
-    classes = [
-        i for i in decls if isinstance(i, declarations.class_t)]
-
-    typedefs = [
-        i for i in decls if isinstance(i, declarations.typedef_t)]
-
-    variables = [
-        i for i in decls if isinstance(i, declarations.variable_t)]
-
-    assert "a" in [class_.name for class_ in classes]
-    if len(classes) == 2:
-        for c in known_classes:
-            assert c in [cl.name for cl in classes]
-    elif len(classes) == 3:
-        for c in known_classes_llvm39:
-            # This is for llvm 3.9
-            assert c in [cl.name for cl in classes]
-
-    if len(typedefs) == 5:
-        # This is for llvm 3.9. The class __va_list_tag struct is still
-        # there but the typedef is gone
-        for t in known_typedefs_llvm39:
-            assert t in [ty.name for ty in typedefs]
-        assert "__NSConstantString_tag" in [class_.name for class_ in classes]
-        assert "__NSConstantString" in [ty.name for ty in typedefs]
-    else:
-        for t in known_typedefs:
-            assert t in [ty.name for ty in typedefs]
-
-    # 4 variables in __va_list_tag, and 4 more in __NSConstantString_tag
-    # for llvm 3.9
-    assert len(variables) == 4 or len(variables) == 8
-
-
-def test_remove_va_list_tag():
-
-    if platform.system() == 'Windows':
-        return True
-
-    config = autoconfig.cxx_parsers_cfg.config.clone()
-
-    config.flags = []
-    src_reader = parser.source_reader_t(config)
-    decls = declarations.make_flatten(src_reader.read_string(__code))
-
-    classes = [
-        i for i in decls if isinstance(i, declarations.class_t)]
-
-    typedefs = [
-        i for i in decls if isinstance(i, declarations.typedef_t)]
-
-    variables = [
-        i for i in decls if isinstance(i, declarations.variable_t)]
-
-    tag = "__va_list_tag"
-
-    assert tag not in [class_.name for class_ in classes]
-    assert "a" in [class_.name for class_ in classes]
-    assert len(classes) == 1
-
-    assert tag not in [ty.name for ty in typedefs]
-    if len(typedefs) == 4:
-        # This is for llvm 3.9
-        for t in known_typedefs_llvm39:
-            assert t in [ty.name for ty in typedefs]
-        assert "__NSConstantString_tag" not in \
-            [class_.name for class_ in classes]
-        assert "__NSConstantString" not in \
-            [ty.name for ty in typedefs]
-    else:
-        for t in known_typedefs:
-            assert t in [ty.name for ty in typedefs]
-
-    assert tag not in [var.decl_string.split("::")[1] for var in variables]
-    assert len(variables) == 0