diff --git a/blueprintcompiler/gir.py b/blueprintcompiler/gir.py
index cb73961..e57fe50 100644
--- a/blueprintcompiler/gir.py
+++ b/blueprintcompiler/gir.py
@@ -25,7 +25,8 @@ from functools import cached_property
 import gi  # type: ignore
 
 gi.require_version("GIRepository", "2.0")
-from gi.repository import GIRepository  # type: ignore
+gi.require_version("GLib", "2.0")
+from gi.repository import GIRepository, GLib  # type: ignore
 
 from . import typelib, xml_reader
 from .errors import CompileError, CompilerBugError
@@ -64,11 +65,13 @@ def collect_gir_search_paths():
     if _gir_search_paths_initalized:
         return
 
+    base_paths = [
+        GLib.get_user_data_dir(),
+        *GLib.get_system_data_dirs(),
+    ]
+
     global _gir_search_paths
-    if data_paths := os.environ.get("XDG_DATA_DIRS"):
-        _gir_search_paths += [
-            os.path.join(path, "gir-1.0") for path in data_paths.split(os.pathsep)
-        ]
+    _gir_search_paths = [os.path.join(path, "gir-1.0") for path in base_paths]
     _gir_search_paths_initalized = True