diff --git a/blueprintcompiler/language/__init__.py b/blueprintcompiler/language/__init__.py
index ad4c6bc..91407b5 100644
--- a/blueprintcompiler/language/__init__.py
+++ b/blueprintcompiler/language/__init__.py
@@ -11,9 +11,11 @@ from .gtk_size_group import Widgets
 from .gtk_string_list import Strings
 from .gtk_styles import Styles
 
-OBJECT_HOOKS = [menu]
+from .common import *
 
-OBJECT_CONTENT_HOOKS = [
+OBJECT_HOOKS.children = [menu]
+
+OBJECT_CONTENT_HOOKS.children = [
     Signal, A11y, Styles, Layout, mime_types, patterns, suffixes, Widgets, Items,
     Strings,
 ]
diff --git a/blueprintcompiler/language/common.py b/blueprintcompiler/language/common.py
index e6e2d9e..e6f9cca 100644
--- a/blueprintcompiler/language/common.py
+++ b/blueprintcompiler/language/common.py
@@ -26,3 +26,7 @@ from ..lsp_utils import Completion, CompletionItemKind
 from ..parse_tree import *
 from ..parser_utils import *
 from ..xml_emitter import XmlEmitter
+
+
+OBJECT_HOOKS = AnyOf()
+OBJECT_CONTENT_HOOKS = AnyOf()
diff --git a/blueprintcompiler/language/imports.py b/blueprintcompiler/language/imports.py
new file mode 100644
index 0000000..f3ddab7
--- /dev/null
+++ b/blueprintcompiler/language/imports.py
@@ -0,0 +1,70 @@
+# imports.py
+#
+# Copyright 2022 James Westman <james@jwestman.net>
+#
+# This file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 3 of the
+# License, or (at your option) any later version.
+#
+# This file is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+
+from .common import *
+
+
+class GtkDirective(AstNode):
+    grammar = Statement(
+        Match("using").err("File must start with a \"using Gtk\" directive (e.g. `using Gtk 4.0;`)"),
+        Match("Gtk").err("File must start with a \"using Gtk\" directive (e.g. `using Gtk 4.0;`)"),
+        UseNumberText("version").expected("a version number for GTK"),
+    )
+
+    @validate("version")
+    def gtk_version(self):
+        if self.tokens["version"] not in ["4.0"]:
+            err = CompileError("Only GTK 4 is supported")
+            if self.tokens["version"].startswith("4"):
+                err.hint("Expected the GIR version, not an exact version number. Use `using Gtk 4.0;`.")
+            else:
+                err.hint("Expected `using Gtk 4.0;`")
+            raise err
+
+
+    @property
+    def gir_namespace(self):
+        return gir.get_namespace("Gtk", self.tokens["version"])
+
+
+    def emit_xml(self, xml: XmlEmitter):
+        xml.put_self_closing("requires", lib="gtk", version=self.tokens["version"])
+
+
+class Import(AstNode):
+    grammar = Statement(
+        "using",
+        UseIdent("namespace").expected("a GIR namespace"),
+        UseNumberText("version").expected("a version number"),
+    )
+
+    @validate("namespace", "version")
+    def namespace_exists(self):
+        gir.get_namespace(self.tokens["namespace"], self.tokens["version"])
+
+    @property
+    def gir_namespace(self):
+        try:
+            return gir.get_namespace(self.tokens["namespace"], self.tokens["version"])
+        except CompileError:
+            return None
+
+    def emit_xml(self, xml):
+        pass
diff --git a/blueprintcompiler/parse_tree.py b/blueprintcompiler/parse_tree.py
index 00ef0c7..10fac2d 100644
--- a/blueprintcompiler/parse_tree.py
+++ b/blueprintcompiler/parse_tree.py
@@ -324,7 +324,14 @@ class AnyOf(ParseNode):
     """ ParseNode that attempts to match exactly one of its children. Child
     nodes are attempted in order. """
     def __init__(self, *children):
-        self.children = [to_parse_node(child) for child in children]
+        self.children = children
+
+    @property
+    def children(self):
+        return self._children
+    @children.setter
+    def children(self, children):
+        self._children = [to_parse_node(child) for child in children]
 
     def _parse(self, ctx):
         for child in self.children:
diff --git a/blueprintcompiler/parser.py b/blueprintcompiler/parser.py
index b9c5e4f..ede452c 100644
--- a/blueprintcompiler/parser.py
+++ b/blueprintcompiler/parser.py
@@ -40,7 +40,7 @@ def parse(tokens) -> T.Tuple[ast.UI, T.Optional[MultipleErrors]]:
             UseIdent("name"),
             ":",
             AnyOf(
-                *OBJECT_HOOKS,
+                OBJECT_HOOKS,
                 object,
                 value,
             ).expected("a value"),
@@ -82,7 +82,7 @@ def parse(tokens) -> T.Tuple[ast.UI, T.Optional[MultipleErrors]]:
         [
             "{",
             Until(AnyOf(
-                *OBJECT_CONTENT_HOOKS,
+                OBJECT_CONTENT_HOOKS,
                 binding,
                 property,
                 child,
@@ -116,7 +116,7 @@ def parse(tokens) -> T.Tuple[ast.UI, T.Optional[MultipleErrors]]:
             ast.GtkDirective,
             ZeroOrMore(ast.Import),
             Until(AnyOf(
-                *OBJECT_HOOKS,
+                OBJECT_HOOKS,
                 template,
                 object,
             ), Eof()),